New Developments in Biotechnology:

Field-Testing Engineered Organisms:

Genetic and Ecological Issues

May 1988

NTIS order #PB88-214101
Recommended Citation:

U.S. Congress, Office of Technology Assessment, New Developments in BiotechnologyField-Testing Engineered Organisms: Genetic and Ecological Issues, OTA-BA-350 (Washington, DC: U.S. Government Printing Office, May 1988).

Library of Congress Catalog Card Number 88-600522

For sale by the Superintendent of Documents

U.S. Government Printing Office, Washington, DC 20402-9325

(order form can be found in the back of this report)
Foreword

Since the discovery of recombinant DNA technology in the early 1970s much attention has focused on the potential benefits and risks presented by the new abilities of

researchers to manipulate DNA. The importance of ecological issues was heightened

in 1982 with the proposal by researchers to field test bacteria engineered to reduce

crop losses due to frost damage. Additional pressures have come to bear as a result

of developments in the economics of American agriculture and with foreign trade imbalances. In this special report OTA analyzes some of the scientific and public opinion

issues surrounding the planned introduction of genetically engineered organisms into

the environment.

The assessment of New Developments in Biotechnology was requested by the House

Committee on Energy and Commerce and the House Committee on Science, Space, and

Technology. The first publication in the series was Ownership of Human Tissues and

Cells, and the second was Public Perceptions of Biotechnology. Subsequent studies will

examine U.S. investment in biotechnology and issues relevant to the patenting of plants,

animals, and microorganisms. This third report in the series illustrates a range of options for congressional action in three major areas of public policy related to this application of biotechnology:

● the criteria for review of planned introductions for potential risk,

● the administrative mechanisms for applying such review criteria, and

● the research base supporting planned introductions.

In gathering information for this study, OTA staff made site visits to the research

facilities or proposed field test sites of seven companies developing engineered organisms for environmental applications or doing similar research. The site visits were made

to California, Pennsylvania, Delaware, Missouri, Hawaii, and Wisconsin. Staff also attended and participated in numerous professional meetings devoted to scientific aspects

of the issue.

OTA was assisted in preparing this study by a panel of advisors and reviewers selected

for their expertise and diverse points of view on the issues covered in the assessment.

Advisory panelists and reviewers were drawn from industry, academia, medicine, professional societies, environmental organizations, public interest groups, and Federal agencies. Written comments were received from 140 individuals on successive drafts of the

report.

OTA gratefully acknowledges the contribution of each of these individuals. As with

all OTA reports, the responsibility for content is OTA’s alone.

u JOHN H. GIBBONS

Director

,,.

Ill
New Developments in Biotechnology

Advisory Panel

Bernadine P. Healy, Panel Chair

The Cleveland Clinic Foundation

Cleveland, OH

Timothy B. Atkeson

Steptoe & Johnson

Washington, DC

David Blumenthal

Brigham and Women’s Hospital Corporation

Boston, MA

Hon. Edmund G. Brown, Jr.

Reavis & McGrath

Los Angeles, CA

Nancy L. Buc

Weil, Gotshal & Manges

Washington, DC

Mark F. Cantley

Concertation Unit for Biotechnology in Europe

Brussels, Belgium

Alexander M. Capron

University of Southern California

Los Angeles, CA

Jerry D. Caulder

Mycogen Corp.

San Diego, CA

Lawrence I. Gilbert

The University of North Carolina

Chapel Hill, NC

Conrad A. Istock

The University of Arizona

Tucson, AZ

Edward L. Korwek

Hogan and Hartson

Washington, DC

Tsune Kosuge

University of California, Davis

Davis, CA

Richard Krasnow

Institute for International

Washington, DC

Sheldon Krimsky

Tufts University

Medford, MA

William E. Marshall

Education

Pioneer Hi-Bred International, Inc.

Johnston, IA

Ronald L. Meeusen

Rohm and Haas Co.

Spring House, PA

Robert B. Nicholas

Nash, Railsback & Plesser

Washington, DC

Eric J. Stanbridge

University of California, Irvine

Irvine, CA

James M. Tiedje

Michigan State University

East Lansing, MI

Kunio Toriyama

ZEN-NOH

Tokyo, Japan

Pablo D.T. Valenzuela

Chiron Corp.

Emeryville, CA

Thomas E. Wagner

Ohio University

Athens, OH

NOTE: OTA appreciates and is grateful for the valuable assistance and thoughtful critiques provided by the advisory panel

members. The panel does not, however, necessarily approve, disapprove, or endorse this report. OTA assumes full

responsibility for the report and the accuracy of its contents.

iv
Field-Testing Engineered Organisms

OTA Project Staff

Roger C. Herdman, Assistant Director, OTA Health and Life Sciences Division

Gretchen S. Kolsrud, Biological Applications Program Manager

Gary B. Ellis, Project Director

Luther Val Giddings, Study Director

Robyn Y. Nishimi, Analyst

Kevin W. O’Connor, Analyst

Support Staff

Sharon Kay Oatman, Administrative Assistant

Linda S. Rayford, Secretary/Word Processing Specialist

Barbara V. Ketchum, Clerical Assistant

Contractors

Linda Starke, Editor, Washington, DC

Stephanie L. Forbes, Editor, Bowie, MD

David A. Andow, University of Minnesota, St. Paul, MN

John M. Boyle, Louis Harris and Associates, Inc., Washington, DC

William A. Check, Medical & Scientific Communications, Atlanta, GA

Ellen W. Chu, Scientific & Technical Editing, Kirkland, WA

David C. Coleman, University of Georgia, Athens, GA

C.N. Dahm, University of New Mexico, Albuquerque, NM

Andrew P. Dobson, University of Rochester, Rochester, NY

James R. Gosz, University of New Mexico, Albuquerque, NM

Fred Gould, North Carolina State University, Raleigh, NC

Susan S. Hirano, University of Wisconsin, Madison, WI

Robert E. Hodson, University of Georgia, Athens, GA

Conrad A. Istock, University of Arizona, Tucson, AZ

Kathleen H. Keeler, University of Nebraska, Lincoln, NE

D. Matthew Knain, Louis Harris and Associates, Inc., Washington, DC

Richard E. Lenski, University of California, Irvine, CA

Bruce R. Levin, University of Massachusetts, Amherst, MA

Simon A. Levin, Cornell University, Ithaca, NY

Adrianne Massey, North Carolina State University, Raleigh, NC

Elliott A. Norse, Washington, DC

Stuart L. Pimm, University of Tennessee, Knoxville, TN

Frances E. Sharples, Oak Ridge National Laboratory, TN

S.S. Snapp, University of Minnesota, St. Paul, MN

P.S. Teng, University of Minnesota, St. Paul, MN

Christen D. Upper, University of Wisconsin, Madison, WI

Gabor Vali, University of Wyoming, Laramie, WY

Acknowledgment to Other OTA Staff

Robert Cook-Deegan, Senior Associate, Biological Applications Program

Robert Friedman, Senior Associate, Oceans and Environment Program
OTA/National Science Foundation Workshop

Environmental Applications of Recombinant DNA Organisms:

Genetic Issues, Nov. 21-22, 1985

David T. Kingsbury, Workshop Chair

National Science Foundation

Deb K. Chatterjee

Environmental Protection Agency

Gulf Breeze, FL

Ron Chiarello

IGB Products, Ltd.

San Leandro, CA

Michael T. Clegg

University of California, Riverside

James Collins

Arizona State University

Tempe, AZ

William R. Engels

University of Wisconsin

Madison, WI

Patrick Flanagan

National Science Foundation

Washington, DC

Garrett Hardin

University of California, Santa Barbara

Santa Barbara, CA

Philip Harriman

National Science Foundation

Washington, DC

W. Frank Harris

National Science Foundation

Washington, DC

Washington, DC

Bruce Levin

University of Massachusetts

Amherst, MA

Lois K. Miller

University of Georgia

Athens, GA

Stephen J. O’Brien

National Cancer Institute

Frederick, MD

Mark Obukowicz

Monsanto Company

St. Louis, MO

Philip Regal

University of Minnesota

Minneapolis, MN

James A. Shapiro

University of Chicago

Chicago, IL

James Tiedje

Michigan State University

East Lansing, MI

Richard G. Wiegart

University of Georgia

Athens, GA

NOTE: OTA appreciates and is grateful for the valuable assistance and thoughtful critiques provided by the workshop participants. The

workshop participants do not, however, necessarily approve, disapprove, or endorse this report. OTA assumes full responsibility

for the report and the accuracy of its contents.

vi
Contents

Page

Chapter I: Summary, Policy Issues, and Options for Congressional Action . . . . . . . . . . . . . . . . . . 3

Chapter 2: Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

Chapter 3: The Regulatory Regime and the Role of Public Perception. . . . . . . . . . . . . . . . . . . . . . 45

Chapter 4: Genetic Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71

Chapter 5: Ecological Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85

Chapter 6: Risk Assessment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .................109

Appendix A: Pending and Potential Environmental Applications of Genetically

Engineered Organisms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. ...125

Appendix B: List of Contractor Documents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. ....134

Appendix C: Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .............135

Appendix D: Glossary of Acronyms and Terms. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .139

Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ...............143

vii
Chapter 1

Summary, Policy Issues,

and options for

Congressional Action

“The greatest service which can be rendered any country is, to add a useful plant

to its culture.”

Thomas Jefferson

“The Papers of Thomas Jefferson”

(Accession No. 39161),

Library of Congress, 1800

“one must learn by doing the thing, for although you think you know it you have

no certainty until you try.”

Sophocles

496(?)-406 BCE
CONTENTS

Anticipated Applications . . . . . . . . . . . . . . ● . . . . . . . . . . . . . . . . . . . . .

Plants ● . . . . . . . . . . . . . . ● * $ * * . ....**.** ● . . . . . . . . . . . . . . •~*~.

Animals . . . . . . . . . . . . . . . . . . . . . . . . . ..******.*.**** .. **.***.

Micro-organisms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

The Role of Public Perception and the Regulatory Regime. . . . . . . .

The Effects of Public Perception . . . . . .~. ... .~. ..~...

The Existing Regulatory Framework . . . . . . . . . . . . . . . .

Genetic Considerations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

What Researchers Know About Gene Transfer . . . . . . .

Predicting Potential Effects . . . . . . . . . . . . . . . . . . . . . . . .

Monitoring Gene Transfer . . . . . . . . . . . . . . . . . . . . . . . . .

Inhibiting Gene Transfer . . . . . . . . . . . . . . . . . . . . . . . . . .

Ecological Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . .

Genetically Engineered Organisms and Exotic Species . .

Potential Impact on Populations or Communities . . . . . .

Potential Impact on Ecosystem Processes . . . . . . . . . . . .

Risk Assessment . . . . . . . . . . . . . . . . . . . . . .+....... . . . . .

Must All Planned Introductions Be Reviewed? . . . . . . . .

Micro-organisms v. Macro-organisms . . . . . . . . . . . . . . . .

Implications for Research. . . . . . . . . . . . . . . . . . . . . . . . . .

Policy Issues and Options for Congressional Action . . . . . .

Box

A. The

Figure

I-1. The

Table

Nitrogen Cycle..

Box

Pressure: Antibiotic

Figure

. . . . . . . . . . . . . . . . . . . . . . . . . . .

Genes in

. . . . . . . .

Page

5

5

6

7

8

8

9

11

11

12

13

15

15

17

18

20

22

22

24

25

25

Page

Bacteria. . . . 14

Page

. . . . . . . . . . . 21

l-1. Some Representative Pending and Potential Environmental Applications of

Genetically Engineered Organisms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

l-2. Agencies Responsible for Approval of Commercial

Biotechnology Products. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

l-3. Jurisdiction for Review of Planned Introductions . . . . . . . . . . . . . . . . . . . . . . .

l-4. Comparison of Exotic Species and Genetically Engineered Organisms . . . . . .

Page

6

9

10

17
Chapter 1

Summary, Policy Issues, and

Options for Congressional Action

The development in the 1970s of techniques for

splicing fragments of DNA from different organisms (recombinant DNA technology) opened up

a new science of genetic engineering and a new

industry, “molecular” biotechnology. The roots of

this new industry lie in practices of animal husbandry, agriculture, and fermentation that extend

back for thousands of years. To these ancient practices modern biotechnology adds not only recombinant DNA and cell culture, but also a host of

applications using living organisms to make commercial products. These techniques promise to

reshape many fields; they are now revolutionizing the pharmaceutical industry and medical diagnosis and treatment.

Commercial biotechnology is advancing into

areas that depend on the introduction of genetically engineered organisms into the environment.

These applications could improve old tools or produce new ones for many fields, including agriculture, forestry, toxic waste cleanup, mining, enhanced oil and mineral recovery, and others. In

some cases, such as pest control or toxic waste

management, successful development of biotech -

nological tools could reduce or phase out dependence on older, more hazardous chemical technologies. It is widely expected that the application

of such biological approaches to many human

activities will prove more benign to the environment than traditional technologies.

Planned introductions of genetically engineered

organisms into the environment, often called deliberate release, are not, however, without potential risks, Virtually any organism deliberately introduced into a new environment has a small but

real chance of surviving and multiplying. In some

small subset of such cases, an undesirable consequence might follow. The complexity of even simple ecosystems makes the precise prediction of

such events, and of their consequences, difficult.

This element of uncertainty has led some scientists, public officials, and private citizens to voice

concern about the safety of planned introductions.

Although there is some consensus in the scientific community that the likelihood of unique or

serious problems from planned introductions is

quite low, this opinion is not held unanimously.

Some scientists cite the beneficial introduction of

thousands of species of naturally occurring microbes, plants, and animals that have not adversely

affected the environment. Other scientists point

out that a small fraction of such introductions have

become pests, and suggest that genetic modifications that permit engineered organisms to live in

habitats new to them may, in some cases, present

similar risks. There is also concern among some

scientists that the genetic information newly added to existing species may sometimes produce

undesirable changes in their ecological relationships with other species, or, in rare cases, be

directly transmitted to other species.

The potential benefits of new biotechnologies

have been widely reported. Thus, this report focuses primarily on questions raised by the critics:

How do environmental risks from planned introductions of genetically engineered organisms compare to those encountered in the past in agriculture and commerce? How accurately can scientists

predict the consequences of planned introductions? What genetic and ecological effects are possible or likely? What scientific and social issues

need to be considered in developing risk assessment and mangement procedures? Does the introduction of genetically engineered organisms

require new regulatory procedures to protect

environmental and public health?

It is important to recognize several conditions

that limit generally (though not absolutely) the discussions and conclusions contained in this study:

●

●

Time Scale: This study focuses on the near,

or foreseeable future, generally within about

the next 5 years.

Subject Matten The issues discussed pertain

to small-scale field trials more often than to

3
4

large-scale, commercial applications. The degree to which these issues are relevant to

large-scale, commercial applications should

be revealed by the results of small-scale field

tests.

● Definition: In this study, the term “genetically engineered organism” is used most often

to mean an organism to which genetic material has been added or deleted via recombinant DNA techniques. This usage is not, however, absolute, since some regulatory agencies

(e.g., EPA) presently define the term more

broadly. Some of the genetic or ecological issues discussed in the study might also apply

to organisms produced by means not involving recombinant DNA in the strict sense, such

as cell fusion.

It is possible that new types of planned introductions not now under development, or the

greater scale of some commercial applications,

might introduce questions or concerns in addition to those examined in this study.

Foremost among OTA’s conclusions is that

there are reasons to continue to be cautious,

but there is no cause for alarm. Significant areas

of uncertainty exist, particularly in the realms of

microbial ecology and population dynamics. Widespread environmental or ecological problems do

not now seem likely, however, though they could

emerge in the future. If events develop other than

as planned with a particular introduction, it seems

more likely that the introduced organisms might

become prematurely extinct, and consequently

fail to perform as desired. While increased support for relevant research, both fundamental and

applied, will reduce uncertainties, some questions can be answered only with practical experience.

Even though the range and complexity of applications of new biotechnologies means that the

type of general models used for evaluating the

risks from chemicals cannot be transferred easily, adequate review of planned introductions

is now possible. A review process that involves

critical study of planned introductions by experts

with relevant knowledge and experience offers

confidence of being able to anticipate and prevent most potential problems. As the number of

such completed reviews increases one may expect some generalizable conclusions about the

safety of different types of introductions, This

should enable a consequent streamlining of the

review process. And although almost any category proposed for exemption from review can be

shown wanting through a hypothetical scenario,

it is reasonable to expect that, with experience,

broader categories will emerge for which less rigorous levels of review could be defended. Categories that could be examined now, at least for

abbreviated review, include:

●

●

●

●

organisms that could be produced with previously existing methods (e.g., mutagenesis

and selection) which, if they were, would not

be regulated under existing law;

an organism substantially identical to one that

has already been reviewed and approved for

field testing;

organisms not containing any genetic material from a potential pathogen; or

organisms whose DNA contains nothing new

but marker sequences in non-coding regions.

Regulatory agencies can and should move

promptly to establish at least provisional categories for different levels of review. They should

act subsequently to modify and streamline these

as experience indicates. This will sometimes be

a contentious exercise, but the stakes, in terms

of economic potential and environmental protection, are sufficient that there can be no substitute for common sense leavened by caution and

appropriate flexibility. To guarantee essential public confidence, this also means that such decisions

must be accountable, attributable to specific regulatory bodies, and sustainable by defensible and

public reasoning.

With adequate review none of the small-scale

field tests proposed or probable within the

next several years are likely to result in an

environmental problem that would be widespread or difficult to control. Indeed, greenhouse or microcosm studies are such inadequate

predictors of field performance that in many cases

realistic small-scale field tests are likely to be

the only way potential risks from commercial

scale uses of genetically engineered organisms

can be evaluated. Assuming such small-scale field
5

tests fail to identify areas of significant concern,

there would be no scientific reason not to seek

further experience with field tests or applications

on a larger scale.

It is important to note that modifying organisms

for specific human ends is not new; selective

breeders of plants and animals have been transferring genes for millennia, often creating forms

through centuries of selection that differ from

their original stocks more than the forms produced by recombinant DNA methods. One of the

distinguishing characteristics of the new technologies is that they allow scientists to do many of

the same things as before with previously undreamed of precision and speed. In evaluating the

potential risks associated with these new technologies, the appropriate question is not “How can

we reduce the potential risks to zero?” but "what

are the relative risks of the new technologies

compared with the risks of the technologies

with which they will compete?” Furthermore,

What are the risks posed by over regulating,

or failing to develop fully the new technologies? How do we weigh costs and benefits?

How much review is enough? In most cases the

new potential risks will be qualitatively similar

to the old risks. Sometimes they will be quantitatively less. The potential benefits to be derived

are often substantial.

ANTICIPATED APPLICATIONS

Pending and potential environmental applications of genetically engineered organisms span an

enormous range—enormous in terms of engineered organisms, the diverse environments into

which they will be introduced, and the functions

they are intended to perform (see table 1-1 and

app. A).

Many pending or imminent introductions involve minor genetic alterations to modify an existing function in an existing organism. Most involve the activity of the product (protein) of a single structural gene, More than a dozen small-scale

field tests have already taken place. Applications

for others are pending or anticipated in the near

future,

Plants

To decrease crop losses due to weeds, genes

have been introduced into several plant species

to confer resistance or tolerance to certain herbicides, including glyphosate (Calgene, Davis, CA;

Monsanto, St. Louis, MO), sulfonylurea (Du Pont,

Wilmington, DE), and atrazine (Ciba-Geigy, Greensboro, NC). Depending on the particular herbicide,

this practice could increase or decrease pollution

hazards by stimulating changes in patterns of herbicide use.

Plants have also been engineered better to resist disease. Tobacco plants (valuable for the ease

with which they can be studied) have been transformed to resist crown gall disease (Agracetus,

Middleton, WI). Researchers at Monsanto and at

Washington University (St. Louis, MO) have also

“vaccinated” tobacco and tomato plants against

tobacco mosaic virus by inserting a single virus

gene into the plant genome. Similar results with

the alfalfa mosaic virus suggest that the same

technique may protect many plants against viruscaused diseases.

Pest resistance is another promising area. The

delta-endotoxin gene of the well known and much

used bacterium Bacillus thuringiensis (BT), which

encodes a toxin effective against certain caterpillars, has been inserted into tobacco and tomato

plants.

Investigators are pursuing many other applications, including drought or saline resistant plants.

Recombinant DNA and cell fusion techniques are

being used to create new crop varieties, improve

the nutritional qualities of some species, and increase algal production of substances used in the

food industry. Future endeavors might include enhancing the ability of certain algae to sequester

heavy metals from seawater, and introducing

genes encoding compounds that protect seeds

against insects. Such engineered seed protection

could improve long-term storage of certain crops.
6

Animals resistance, or (livestock) coat characteristics. The

types of alterations being pursued and the conMost recombinant DNA work on animals focuses fined agricultural settings of most altered animals

on altering livestock, poultry, or fish to improve both provide continuity between modern and hisreproductive performance, weight gain, disease torical biotechnology.

Table 1.1 .—Some Representative Pending and Potential Environmental Applications

of Genetically Engineered Organisms

MICRO-ORGANISMS PLANTS

Bacteria as pesticides. “ice-minus” bacteria to reduce

frost damage to agricultural crops.

Bacteria carrying Bacillus thuringiensis toxin to reduce

t loss of corn crops to black cutworm.

Mycorrhizal fungi to increase plant growth rates by improving efficiency of root uptake of nutrients.

Plant symbionts. Nitrogen-fixing bacteria to increase

nitrogen available to plants, and decrease need for fertilizers,

Toxic waste disposal. Bacteria engineered to enhance

their existing abilities to degrade compounds found in

sludge in waste treatment plants.

Bacteria engineered to enhance their abilities to degrade

compounds in landfills, dumps, runoff deposits, and

contaminated soils.

Heavy metal recovery. Engineered enhancements possible to several species of bacteria now used to recover

metals from low-grade ores (e.g., copper and cobalt).

Pollution control. Possible increased utility of bacteria in

purifying water supplies of phosphorus, ammonia, and

other compounds.

Viruses as pesticides. insect viruses with narrowed host

specificity or increased virulence against specific

agricultural insect pests, including cabbage looper,

pine beauty moth, cutworms, and other pests.

Myxoma virus modified so as to restore its virulence

against rabbits (which became resistant during early biocontrol efforts in Australia).

Viruses as vaccines. Vaccines against human diseases

including:

—hepatitis A and B

—polio

—herpes simplex (oral and genital)

—malaria

—acquired immunodeficiency syndrome

—rabies

—respiratory syncitial virus

Vaccines against animal diseases including:

—swine pseudorabies

—swine rotavirus

—vesicular stomatitis (cattle)

–foot and mouth disease (cattle)

—bovine rotavirus

—rabies (cattle, other mammals)

—sheep foot rot

—infectious bronchitis virus (chickens)

—avian erythroblastosis

—sindbis virus (sheep, cattle, chickens)

Muitivalent vaccines. Vaccines possible for antigenically

complex diseases such as:

—malaria

—sleeping sickness

—schistosomiasis

Herbicide resistance or tolerance to:

Glyphosate

Atrazine

Sulfonyiurea (chlorosulfuron and sulfometuron)

imidazolinone

Bromoxynil

Phosphinotricin

Disease resistance to:

Crown gall disease (tobacco)

Tobacco mosaic virus (and related viruses)

Potato leaf roll virus

Pest resistance

BT-toxin-protected crops, including tobacco (principally

as research tool) and tomato.

Seeds with enhanced anti-feedant content to reduce

losses to insects while in storage.

Enhanced tolerance to environmental factors, including:

Salt

Drought

Temperature

Heavy metals

Nitrogen-fixation enhancements

Nonlegumes enhanced to fix nitrogen, independent of

association with symbiotic bacteria.

Engineered marine algae

Algae enhanced to increase production of such

compounds as B-carotene and agar, or to enhance

ability to sequester heavy metals (e.g., gold and

cobalt) from seawater.

Forestry

Trees engineered to be resistant to disease or

herbicides, to grow faster, or to be more tolerant to

environmental stresses.

ANIMALS

Livestock and poultry

Livestock species engineered to enhance weight gain

or growth rates, reproductive performance, disease

resistance, or coat characteristics.

Livestock animals engineered to function as producers

for pharmaceutical drugs, especially of mammalian

compounds that require post-synthesis modifications

in the cell.

Fish

Triploid salmon produced by heat shock for use as

game fish in lakes and streams.

Fish with enhanced growth rates, cold tolerance, or

disease resistance for use in aquaculture.

Triploid grass carp for use as aquatic weed control

agents,

SOURCE: Office of Technology Assessment, 1988.
?

%

m

Photo credit” Hideo Yamagishi, Kyoto University

Electron micrograph of DNA double helix,

“rim” = nanometer= one-billionth of a meter.

Transferring animal growth hormone genes or

exposing fish embryos to abnormally high temperatures to change chromosome number are

other successful techniques. Genetic engineering

also holds promise for altering insect pests for

use in integrated pest management schemes which

rely on biological as well as chemical controls.

Micro-organisms

Bacteria, viruses, and fungi offer the molecular biologist some of the best candidates for genetic

engineering. Molecular genetics originated in experiments with certain species of these organisms:

Of greatest use in this research is the common

inhabitant of the human gut, Escherichia coli.

Other bacteria of medical importance include

Salmonella, Streptococcus, and Bacillus. Yeast, Saccharomyces cerevisiae, and other fermenters such

as Lactobacillus have also been important in the

evolution of molecular genetics, as have several

bacterial and plant viruses. The genetic structure

and functioning of these micro-organisms are

among the best understood. Microbes are small

and easy to handle in the laboratory, and they reproduce rapidly. Enormous numbers can be examined in a short time.

But the special qualities of microorganisms also

present some unique problems. Because they are

microscopic, special techniques are required to

monitor their survival or dispersal. Their rapid

growth rates under favorable conditions and the

ability of some species to exchange genetic material make transfer of altered genetic material

among some microbes less predictable than among

larger organisms.

The ubiquity of microbes (they are literally

everywhere; a gram of soil will commonly contain a billion microbes) and their key roles in the

fundamental ecological processes of energy flow

and nutrient cycles have led to some concerns

about the potential for disruption of these processes if large-scale introductions of genetically

engineered microbes take place. Some scientists,

however, point to the high degree of functional

redundancy among members of microbial communities, which acts as a buffer against far-

-reaching perturbations. They also cite the lack

of negative consequences in considerable experience over the last century, during which large

numbers of microbes have been introduced into

the environment for agricultural and pest control purposes, and for pollution and waste treatment, and conclude from these observations that

problems are not likely.

Many promising environmental applications of

engineered micro-organisms are being developed.

One bacterial application deletes the gene for a

cell membrane protein that acts as a nucleus for

frost formation. The resulting so-called ice-minus

bacteria, derived from species that normally live

on plant surfaces, could help reduce crop losses

from frost. In other applications, the BT toxin gene

has been inserted directly into some bacteria. In
8

one case researchers hope the transformed bacteria, adapted to live on the surfaces of the roots

of corn plants, will help reduce corn crop losses

to insect larvae. In another, the transformed bacteria are killed and treated to produce a particle

containing BT toxin that can then be applied as

a topical insecticide. Other bacteria are being engineered to degrade specific toxic compounds found

in industrial waste or sludge. Many bacteria can

break down toxic compounds naturally, and there

is the potential of enhancing their ability to consume petroleum, solvents, benzene derivatives,

or halogenated hydrocarbons like polychlorinated

biphenyls, polybrominated biphenyls, or dioxin,

although these applications are likely to be some

years away.

One important application that has received a

great deal of research attention is enhancing or

transferring the capacity to make atmospheric nitrogen biologically usable, or to “fix” nitrogen. If

managed well, this holds significant potential for

reducing the amount of nitrogen fertilizer required in agriculture, thus reducing the costs and

the problems associated with nitrate contamination of runoff water. BioTechnica International,

Inc. (Cambridge, MA) is preparing to field test a

variety of a naturally occurring bacterium with

enhanced nitrogen-fixing ability. It is likely that

the more ambitious goal of transferring nitrogenfixing capacity directly to plants is many years

from realization.

Viruses, especially those that affect insects, have

potential as pesticides as well as vaccines for both

animals and humans. Recent efforts have been

directed toward engineering vaccinia viruses to

produce vaccines for hepatitis B, herpes simplex,

influenza, and hookworm as well as vaccines

against such animal diseases as rabies, vesicular

stomatitis (a disease of cattle), and others. These

are usually produced by using recombinant DNA

methods to separate the virus genes that will evoke

immune responses in the infected organisms from

the genes encoding the proteins responsible for

disease. When the latter are removed, a number

of the problems historically associated with attenuated or live virus vaccines in common use

today are eliminated. Multivalent vaccines, which

could be effective against several diseases at once

or against complex diseases, are also being developed.

THE ROLE OF PUBLIC PERCEPTION AND

THE REGULATORY REGIME

In many ways, the wide range of organisms and

potential uses complicates the regulatory picture

for the new industry of modern biotechnology

because the critical issues differ from application to application. Policy makers need to rely

on sound scientific review and weigh carefully

any potential risks against anticipated benefits of

each new planned introduction. A flexible review process, founded in critical scientific

evaluation and adaptable to the requirements

of particular cases, can serve industry and the

public interest well without being unduly burdensome.

The Effects of Public Perception

Public perception of the benefits and risks

of biotechnology is as likely to influence future industry developments as is formal risk

assessment by scientific groups and public

officials. When proposing to field test genetically

engineered organisms, scientists—whether in academic institutions or industry–must be prepared

to work with local citizens and officials. Recent

experience in several communities and an OTAcommissioned survey have shown that public

opinion is ambivalent and can be vocal with respect to planned introductions of genetically engineered organisms. In several cases public opinion has thwarted or delayed proposed field tests.

In other communities opposition has been minimal, and in some cases vocal elements have been

supportive. (Ch. 3 includes descriptions of the role

of public perception in about a dozen local communities where field tests have been proposed

or carried out.)

As in science and technology generally, public

interest in the new biotechnologies is high. Al-
9

though people are concerned about the morality

and safety of genetic engineering, they believe that

research should continue. Most say they believe

the benefits will ultimately justify the risks. Indeed, the public claims to be willing to accept relatively high probabilities of risk to the environment

(provided oversight is sufficient) in exchange for

the benefits that might accrue from environmental

applications of genetically engineered organisms.

The Existing Regulatory Framework

Shortly after recombinant DNA technology appeared and began to be more widely used during

the 1970s, concerns were raised about its safety.

In an unprecedented move, scientists developing

the new techniques met in 1975 at the Asilomar

Conference Center (Pacific Grove, CA), and agreed

to control stringently their own research until the

safety of the new technology could be assured.

In 1976, the National Institutes of Health (NIH) issued the first formal guidelines for recombinant

DNA research. As research continued, and as scientists learned more about the safety of genetically engineered organisms, initial fears proved

excessive, the guidelines were repeatedly revised,

and the controls on recombinant DNA research

in the laboratory were relaxed.

Some of the safety concerns that have surfaced over the planned introduction of genetically engineered organisms are about issues

quite different from those associated with research confined to a laboratory. Numerous ecological issues not relevant to laboratory work become important when applications move beyond

the laboratory and into the environment, Assuming regulation is appropriate (an assumption challenged by some), who should regulate planned introduction experiments? How should regulatory

agencies assess potential risks? As more and more

products reach field-test stage, the need to answer

these questions becomes more pressing.

The White House Office of Science and Technology Policy published the Coordinated Framework for the Regulation of Biotechnology in June

1986. This document identifies the agencies responsible for approving commercial biotechnology products (table 1-2) and their jurisdictions for

regulating field tests and planned introductions

Table 1-2.—Agencies Responsible for Approval of

Commercial Biotechnology Products

Biotechnology products -. . Responsible agencies

Foods/food additives . . . . . . . . . . . FDA, * FSISa

Human drugs, medical devices,

and biologics . . . . . . . . . . . . . . FDA

Animal drugs. . . . . . . . . . . . . . . . . . FDA

Animal biologics. . . . . . . . . . . . . . . APHIS

Other contained uses . . . . . . . . . . EPA

Plants and animals. . . . . . . . . . . . . APHIS, C FSIS, a F D A

b

Pesticide micro-organisms

released in the environment , EPA, d APHIS C

Other uses (micro-organisms):

Intergeneric combination . . . . . EPA,d APHIS

C

Intrageneric combination:

Pathogenic source organism

1. Agricultural use . . . . . . . APHIS

2. Nonagricultural use . . . . EPA,d APHIS

C

Nonpathogenic source

organisms . . . . . . . . . . . . . . EPA Report

Nonengineered pathogens:

1. Agricultural use . . . . . APHIS

2. Nonagricultural use . . EPA,d APHIS

C

Nonengineered

nonpathogens . . . . . . . . . . . EPA Report

● Designates lead agency where jurisdictions may overlap,

aFSIS, Food Safety end Inspection Service, under the Assistant Secretary Of Agriculture for Marketing and Inspection Services, is responsible for food use.

bFDA IS irrvolvetj when in relation to a food use.

CApHIS An/real and plant Heeith Inspection Service, is involved when the microorganism is plant pest, animal pathogen, or regulated article requiring a permit.

dEpA requirement WiII only apply to environmental release under a “significant

new use rule” that EPA intends to propose.

SOURCE: 51 Fed. Reg. 23339.

(table 1-3). It describes the regulatory policies of

the Environmental Protection Agency (EPA), the

U.S. Department of Agriculture (USDA), and the

Food and Drug Administration (FDA), as well as

the research policies of the National Institutes of

Health (NIH) the National Science Foundation

(NSF), EPA, and USDA. The purpose of the Framework is to enable the agencies to ‘(operate in an

integrated and coordinated fashion [to] cover the

full range of plants, animals, and micro-organisms

derived by the new genetic engineering techniques. ”

At present, FDA relies on its existing policies

for regulating biotechnology products. EPA regulates biotechnology under the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) and

the Toxic Substances Control Act (TSCA). USDA

relies on the Plant Pest Act and related statutes,

while the Occupational Safety and Health Administration has regulatory authority over certain

aspects of biotechnology that relate to workplace

safety.
10

Table 1-3.—Jurisdiction for Review of Planned introductions

Proposed research Responsible agencies

Contained research, no release in environment:

Federally funded . . . . . . . . . . . . . . . . . . . . . . . . . .

Nonfederally funded . . . . . . . . . . . . . . . . . . . . . . .

Foods/food additives, human drugs, medical

devices, biologics, animal drugs:

Federally funded ., . . . . . . . . . . . . . . . . . . . . . . . .

Nonfederally funded . . . . . . . . . . . . . . . . . . . . . . .

Plants, animals and animal biologics:

Federally funded . . . . . . . . . . . . . . . . . . . . . . . . . .

Nonfederally funded . . . . . . . . . . . . . . . . . . . . . . .

Pesticide microorganisms:

Genetically engineered:

Intergeneric . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Pathogenic intrageneric. . . . . . . . . . . . . . . . . .

Intrageneric nonpathogen

Nonengineered:

Nonindigenous pathogens . . . . . . . . . . . . . . .

Indigenous pathogens . . . . . . . . . . . . . . . . . .

Nonindigenous nonpathogen . . . . . . . . . . . . .

Other uses (micro-organisms) released in the

environment:

Genetically engineered:

lntergeneric organisms

Federally funded . . . . . . . . . . . . . . . . . . . . . .

Commercially funded . . . . . . . . . . . . . . . . . .

Intrageneric organisms

Pathogenic source organisms

Federally funded . . . . . . . . . . . . . . . . . . . .

Commercially funded . . . . . . . . . . . . . . . .

Intrageneric combination

Nonpathogenic source organisms . . . . . . .

Nonengineered . . . . . . . . . . . . . . . . . . . . . . . . . . .

Funding agency,=

NIH or S&E voluntary review, APHISC

FDA, b NIH guidelines and review

FDA, b NIH voluntary review

Funding agency=, APHISC

APHIS C, S&E voluntary review

EPAd

, APHISC, S&E voluntary review

EPAd

, APHISC, S&E voluntary review

EPAd

, S&E voluntary review

EPAd

, APHIS

EPAd

, APHIS

EPAd

Funding agency=, APHISC, EPAd

EPA, APHIS, S&E voluntary review

Funding agency,= APHIS, C EPAd

APHIS C, EPAd (if nonagricultural use)

EPA Report

EPA Report*. APHISC

.

● Designates lead agency where jurisdictions may overlap.

aReview and approval of research protocols conducted by NIH, S&E, or NSF.

bApHIS i~~ue~ permits for the importation and domestic $hipment of certain plants and animals, piant pEWtS and animal pathogens, and for the shipment or release in the environment of regulated articles.

CEPA jurisdiction for research on a plot greater thari 10 acres.

dEpA ~ev~ews federally funded environmental research only when it is for commercial pUrpOSeS.

Abbreviations: NIH = National Institutes of Health; S&E = United States Department of Agriculture Science and Education,

APHIS = Animal and Plant Health Inspection Service; EPA = Environmental Protection Agency

SOURCE: 51 Fed. Reg. 23305

Several problems—virtually none of them new

or unique to biotechnology-face regulators, particularly in the area of planned introductions of

genetically engineered organisms: ●

●

●

●

Scope: Should regulation be product-based,

or is there a foundation for basing it on the

processes used in producing the products?

Definitions: Common definitions of critical

terms such as deliberate release into the envi- ●

ronment, and pathogen, need to be established.

Risk Assessment and Management: Decision makers must perform a complex balanc- ●

ing act—weighing the known risks and benefits of existing

potential risks and

nologies.

technologies against the

likely benefits of new techJurisdiction of Federal Agencies Regulating Biotechnology: Potential conflicts between overlapping jurisdictions of Federal

agencies should be prevented from interfering with appropriate regulation.

Role of State and Local Governments: Local zoning and environmental statutes are important determinants of policy that may affect future tests and applications.

Public Perception: Whatever the scientific

and regulatory judgments, public perception
11

will strongly affect the conduct of field tests and others (discussed in ch. 3). As of May 1988,

and the final outcome of commercial appli- it had been in use for 23 months, and will soon

cations of biotechnology. need to be formally evaluated to determine if there

The Coordinated Framework appears to provide are problems it does not cover adequately.

means for dealing with most of these problems

GENETIC CONSIDERATIONS

The planned introduction of genetically engineered organisms that can survive and multiply

raises a variety of genetical questions, many of

which are relevant only if there is a reasonable

probability that the introduced organisms could

have a deleterious impact on the environment or

public health. The likelihood of such a consequence depends on the nature of the organism

and on the new genetic information it carries. It

also depends on whether the new genetic material in the altered organism remains where it was

inserted, performing as designed, or is transferred

to a new location in a nontarget organism, possibly performing in an unanticipated manner. It may

therefore be important to consider, where such

occurrence is plausible, the probability that novel

genetic material will spread beyond the engineered organisms at the release site. The migration of genetic material from one organism to

another by means other than germ cells is called

horizontal transfer. In bacteria, horizontal transfer is the transmission of genetic information from

one contemporaneous bacterial cell to another by

whatever means.

What are the potential outcomes of such transfer? Are they beneficial, harmful, or of no consequence? How can the movement of genetic material be observed? What techniques or constraints

can limit the frequency or mitigate any potentially

adverse consequences of gene transfer? Special

considerations exist for each set of organisms.

What Researchers Know

About Gene Transfer

Gene transfer between species takes place via

a limited number of means, including:

● Hybridization: also known as sexual outcrossing, in plants and animals. In animals this

is generally impossible except with closely re -

●

●

●

●

lated species; it is common in many groups

of plants.

Transformation: the incorporation by bacteria of DNA fragments from the immediate

environment.

Plasmids: circles of DNA that are separate

and replicate independently from the chromosome within cells. Some are self-mobilizable, and can transmit themselves between

compatible cells. Others require the assistance

of mobile plasmids to be transferred.

Viruses nucleic acid (DNA or RNA) packaged

in a protective protein coat (unlike plasmids).

To reproduce, a virus must infect a cell and

take over the host cell’s metabolic machinery.

Viruses can transfer genetic material between

species via “transduction” (see glossary),

Transposons (Transposable Elements) and

Insertion Sequences: DNA sequences carrying one or more genes, and flanked by insertion sequences—short DNA fragments that

are able move to different places within the

cell on the same or a different DNA molecule.

Some of these mechanisms are shared by several classes of organisms, while others are unique

to particular groups. Gene transfer is more likely

in some groups of bacteria, and less easy to control or predict than hybridization in plants or animals. Except where indicated, the following discussion of gene transfer is more relevant to

bacteria than to higher organisms.

Much of what investigators know about gene

transfer comes from laboratory experience. Gene

transfer between bacteria, for example, is well

studied among laboratory populations. Although

the frequency of transfer may be relatively low,

rapid reproduction and large populations mean

that genes can be transmitted into some bacterial

populations quite rapidly, if coupled with the
12

appropriate selection pressures. Among insects,

evolutionary evidence indicates transfer can occur via transposable elements and viruses, but

how often is not known. Similarly, it seems that

some horizontal transmission between disparate

mammalian families may have taken place in the

past, but little evidence exists for transfer in recent times or at appreciable frequencies. Gene

transfer among plants by mechanisms other than

hybridization has not been well studied, and if

it occurs in nature it seems to be quite rare.

The systems of genetic transfer that have been

studied were chosen largely for their amenability to laboratory research. They represent only

a small sample of what actually occurs in nature.

It is clear that with a few exceptions (i.e., between

some closely related animal or insect species, between many higher plants, and between some bacterial species), significant natural obstacles

block most gene flow between species. It is logical to assume, and data support the conclusion,

that natural populations of bacteria (generally less

dense than laboratory populations) experience

lower rates of gene transfer than do laboratory

populations. Questions that remain include:

● How extensively do gene transfer mechanisms observed in the laboratory operate in

nature?

● What are the genetic and environmental conditions under which novel information could

be incorporated into a foreign genome and

subsequently expressed?

● How do populations of organisms limit incursion of new genetic material?

Predicting Potential Effects

Several questions are posed by the introduction

of a recombinant organism into the environment:

What are the conditions that encourage transfer

or maintenance of the inserted genes, and how

likely is it that genes could be transferred beyond

the target site? If transferred, will the new genetic

material be expressed? If transferred and expressed, will there be any environmentally significant consequences, positive or negative? (The

last question is considered more fully in the section on Ecological Considerations.)

Some observers maintain that if it is known that

the gene in question will not move about, the potential consequences of gene transfer should not

be a concern. Others argue that if the modified

organism or gene will cause no problems if it does

spread, then estimating the probability of transfer is unnecessary. Both issues must be addressed

for a balanced evaluation of the potential consequences of a proposed introduction experiment.

A very low probability of transfer multiplied by

a moderate probability of hazard if transfer occurs produces a different situation than if both

probabilities are very low. Of course, a significant

probability of benefit could also offset all or part

of any potential risk.

Other observers argue that it should be assumed

that any introduced genetic material will eventually be transmitted to nontarget species, and that

any consequences should be anticipated. Predicting the consequences and evaluating the risks of

deliberate release requires information about intrinsic and extrinsic factors influencing the magnitude, frequency, and stability of gene transfer.

At a minimum, an analysis of the magnitude

of gene transfer in those cases where it might

be important must address two questions:

How frequently is the genetic material

likely to be transferred to nontarget organisms, especially in comparison to natural background rates?

What is the degree of genetic relationship

between the original organism and the nontarget species?

Intrinsic Factors

Intrinsic factors, which are elements of molecular biology, include characteristics of the host

organism such as the gene involved, the vector

for transferring the gene, and the engineered system itself. Ideally, the biology and natural history

of at least these elements would be well described

and understood. The life cycle, natural history,

and genetic repertoire of the organism from

which a gene is deleted or into which a gene

is inserted should be well understood, and the

gene itself and the mechanisms controlling its

expression in the new host cell should be examined. Substantial “natural history” needs to be
13

understood before proceeding with planned introduction experiments. Reviewers should be sensitive to the possible expression of novel properties of the host organism.

Because a vector can shuttle genetic material

between organisms, familiarity with its host range

and behavior is critical. Some vectors transfer

genetic material by themselves, but some require

outside help. It is important to establish whether

the new gene is mobile or immobile in its new

host cell. Last, the whole construct of the in=

troduced gene, new host, and vector material

needs to be considered. The intracellular configuration of the new gene in the host organism—where it finally resides in host DNA—is

a prime determinant of its potential for movement to new hosts.

Extrinsic Factors

Extrinsic factors are imposed by the environment. The environment where the engineered

organism will be released should be analyzed along

with other environments the organism could encounter. Factors to be considered include:

●

●

●

●

Receptivity of Habitat: Will the engineered

host survive to do its job and reproduce once

introduced? Natural variation in crucial environmental factors is great. Soil systems, and

other natural habitats, may not be sufficiently

fertile to support the addition of large numbers of engineered organisms. Engineered

bacteria will often beat a selective disadvantage when competing with natural populations.

Potential Nontarget Recipients: The most

likely nontarget recipients of engineered

genetic material are genetically similar organisms; the probability of transfer declines with

decreasing similarity or relatedness. If the

engineered gene is already present in the recipient environment, concern about transfer

beyond the intended host is reduced.

Density: The higher the densities of engineered organisms and potential nontarget recipients, the more likely gene transfer is, although in the absence of selection pressure

it will have no consequence.

Selection Pressure: Environmental conditions will determine whether an engineered

gene or organism will persist in a population,

be expressed, or increase in frequency after

introduction. Strong selection for a particular trait-e.g., the presence of an antibiotic—

increases the frequency of a gene or genes

coding for that trait. Selection pressures vary

with each application and depend on the gene

involved, how it is regulated and expressed

in the host, and its interaction with the environment. While it can be expected that many

introductions will be selected against, or at

best be selectively neutral, those introductions

favored by selection are likely to be most successful.

Monitoring Gene Transfer

Convenient, economical, and effective methods

of tracking engineered organisms or the engineered gene(s) they contain are being developed.

These can be divided broadly into selective and

biochemical methods.

Selective tracking methods work by marking

the host chromosome with antibiotic resistance

genes or nutritional markers that confer a competitive advantage under specific conditions.

When exposed to selection pressure exerted by

the antibiotic, for example, organisms carrying

the resistance gene survive and can be easily detected,

Such markers must be carefully screened, however, because those that confer an unintended

competitive advantage-or that mutate to confer

resistance to a whole family of antibiotics-could

lead to problems (see box A). On the other hand,

resistance genes are already present in many naturally occurring soil micro-organisms (a valuable

source of new antibiotics), and antibiotic resistance

markers have long been used in studies of root

ecology with no apparent ill effects.

When using nutritional markers the host chromosome can be marked with a metabolic gene

(e.g., one coding for the production of an enzyme)

not normally found in that organism, Monsanto

researchers have produced such a system with

their insertion of genes for metabolizing the sugar

lactose into the soil bacterium they are studying.
14

Box A.—The Power of Selection Pressure:

Antibiotic Resistance Genes in Bacteria

The bacterium responsible for gonorrhea, Neisseria gonorrhea, was once highly vulnerable to

penicillin. About 30 years ago, penicillin-resistant

strains began appearing. Today, local populations

of highly resistant bacteria have become common.

These resistant populations are most often centered in places where low doses of ampicillin (a

penicillin derivative) are administered continually and indiscriminately as a prophylactic. The

resistance is carried on a plasmid that has been

transferred between bacterial species; the identical plasmid has also been found in the intestinal bacterium Escherichia coli.

Responding to the decline in effectiveness of

penicillin, many physicians have switched to newer,

more effective antibiotics. Spectinomycin is an important one that has been used widely to treat sexually transmitted diseases among U.S. military personnel in the Republic of Korea since 1981. There

have been increasingly frequent reports, however,

of disease strains resistant to this antibiotic. Tests

have revealed that most of these strains are susceptible to penicillin as well as to some other antibiotics.

The key factor in this story is selection pressure.

Indiscriminate and widespread use of one antibiotic

exerts strong and consistent selection pressure on

the target populations (in this case, bacteria), favoring survival of organisms resistant to the antibiotic.

Substituting a selection pressure caused by one

agent for a similar selection pressure caused by

another evokes a similar response to the new agent.

[n the meantime, selection pressure caused by the

First agent (penicillin) having been released, the response (which is energetically expensive for the cell

to maintain) is likely to be dismantled by selection

pressure against energy consumption unnecessary

for survival.

The spread of antibiotic resistance factors is the

sort of adaptive response any population will manifest in response to strong selection pressure. In bacteria, the rapid, worldwide spread of the initial

penicillin resistance was enhanced by highly active

vectors—a conjugative plasmid and a transposon.

Such combinations of intense selection pressure and

actively mobile vectors should be avoided whenever

possible. Responses to such problems should take

advantage of existing, natural selection and capitalize on it.

$OURCE. Office of Technolo&v Assessment, 1988
75

As with antibiotic resistance gene markers, however, this may not always reveal if or how widely

the engineered gene or construct may have traveled to other organisms. The movement of genes

does not always correspond completely to the

movements of the original host organism. To track

the engineered gene itself, a selectable marker

gene must remain where it is inserted, close to

the gene to be tracked; the two would most likely

be transferred together (depending on how closely

they were linked), making it possible to locate the

engineered gene by selecting for and isolating any

cells with the marker gene.

Biochemical methods often rely on gene probes

made with recombinant DNA techniques. A gene

probe is a segment of DNA whose nucleic acid

sequence is complementary to the gene of interest, or to a portion of it. The probe is labeled with

radioactivity or marked with a dye that can be

easily detected in the laboratory. A gene probe

will track a gene even if it is separated from a

tightly linked selection marker or in an organism

that cannot itself be cultured. But to quantify gene

transfer would require general tests of all microbes or DNA in the release environment; processing large numbers of samples would be difficult and expensive.

Inhibiting Gene Transfer

As with detection and tracking, techniques to

prevent or reduce horizontal gene transfer are

not yet well developed. Researchers can either

choose or modify the host and/or the vector so

that introduced organisms have a low probability of persisting in the environment, of transferring genetic material, or both. Specific choices and

modifications will depend on the characteristics

of the organisms involved and the purpose for

which they are engineered.

Whereas gene transfer may be a legitimate concern in planned introductions of some bacteria,

it is unlikely to be a general concern with plant

DNA vectors even when the most active plant vectors are used. Nor is gene transfer a concern in

organisms engineered by gene deletion, though

other traits may then be important.

Reducing or eliminating the use of mobile plasmids and transposons could also help minimize

horizontal transfer. A disarmed transposon with

its engineered gene could no longer separate and

move independently from the chromosome where

it was inserted. This approach of “crippling the

vector” has been successfully used in transferring

the gene for Bacillus thuringiensis toxin into

another common bacterium, Pseudomonas fluorescens; it has also been used to make an immobile vector for insect genetic engineering.

In another approach, an EPA research group

is working to construct a “suicide” bacterium designed to persist in the environment only as long

as it is needed. The bacterium contains a plasmid

carrying a gene that functions only in the presence of the toxic substance the bacterium is designed to clean up; when the toxic substance is

no longer available, the plasmid self-destructs.

The technique is intended to destroy the plasmid

DNA before it can transfer to another host. However, if the host bacterium were killed before the

plasmid were degraded, and the plasmid remained

intact with its inserted gene, the plasmid DNA

could theoretically reinfect another host. But maintaining this assembly costs the cell energy, and

any natural mutation that inactivated the system

would be favored by natural selection.

As advances in nucleotide chemistry make other

techniques possible, new ways of immobilizing

vectors and creating restricted and escape-proof

hosts are being explored. Fundamental research

might be most productive if directed toward increasing understanding of the ecology of different traits. Meanwhile, the genetic implications of

introducing any particular organism into the environment are best considered on an individual

basis.

ECOLOGICAL CONSIDERATIONS

The major ecological concern over planned tial for unforeseen or long-term consequences.

introductions of genetically engineered organ- Although there are enough uncertainties that

isms into the environment stems from the poten- introductions should be approached with cau-
16

tion, a large body of reassuring data, derived

chiefly from agriculture, supports the conclusion that with the appropriate regulatory oversight, the field tests and introductions planned

or probable in the near future are not likely

to result in serious ecological problems.

The results of most planned introductions are

likely to be either beneficial, as planned, or neutral. If only because most planned introductions

are likely to be agricultural, any negative consequences would most likely involve an agricultural

problem, one that might be controlled or mitigated

by crop rotation, introduction of new crop strains,

or other agronomic practice. In those rare circumstances of a negative impact on a natural commu -

Photo credit: Peter Forde, Advanced Genetic Sciences

nity, the consequence seems most likely to be a

transitory disturbance of plant or animal community structure, evidenced by fluctuation in numbers or relative abundance.

The worst possible ecological impact a

planned introduction could have would be to

disrupt a fundamental ecosystem process, e.g.,

the cycling of a mineral or nutrient, or the flow

of energy in an ecosystem; such disruptions

are not, however, among the credible consequences of any introduction that seems likely

within the next several years. The high degree

of functional redundancy among species (particularly microbes) involved with such processes (e.g.,

nutrient cycles or energy flow) and the resilience

and buffering in natural ecosystems are persuasive arguments against the likelihood of such consequences.

Although predicting ecological consequences of

planned introductions is complex, researchers and

regulators are addressing the questions raised by

such introductions. Five criteria have been laid

out for evaluating the likelihood of environmental

impact:

1. Potential for Negative Effects If it is known

that a recombinant organism will have no negAdvanced Genetic Sciences Researcher Julianne Lindemann spraying “ice-minus” bacteria on strawberry plants

in test plot on April 24, 1987. Protective clothing was

required by the California Department of Health Services.

Note reporters and onlookers in immediate background

where coffee and donuts were consumed

without hesitation.
17

2.

3.

4.

5.

ative effects, there is no cause for concern.

But predicting ecological effects, their probability, and assessing whether they are negative or positive is not always straightforward.

Survival: If a genetically engineered organism does not survive, it is unlikely to have

any ecological impact. It is also unlikely to fulfill the purpose for which it was engineered

(unless brief survival was all that was required).

Reproduction: Some applications require

not only survival of the recombinant organism but its reproduction and maintenance.

Increasing numbers could, in some settings,

increase the possibility of unforeseen consequences.

Transfer of Genetic Information: Even if

the engineered organism itself dies out, its

environmental effects could continue if the

crucial genetic material were favored by selection and transferred to and functioned in a

native species, as described in the preceding

section.

Transportation or Dissemination of the

Engineered Organism: A recombinant organism that moves into nontarget environments in sufficient numbers could interact

in unforeseen ways with other populations

or members of other communities.

Genetically Engineered Organisms

and Exotic Species

Although there is much disagreement, some scientists hold that the historical experience presented by introduced exotic species, though imperfect, offers some useful examples of potential

problems to guard against in the planned introduction of genetically engineered organisms.

Every environment contains organisms that

have originated and evolved elsewhere and arrived in their new habitats either independently

or with human assistance, These are called exotics. Some lessons can certainly be learned from

experience with exotics, but important differences

exist between them and most genetically engineered organisms.

Most engineered organisms being studied with

planned introduction in mind will differ from naturally occurring counterparts in only one or a few

genes. Scientists already have a great deal of experience with introductions of new agricultural

crops or cultivars that differ from previously existing varieties by a small number of genes. And

while one or a few genes can have a major impact on such things as host range or pathogenicity, they more often do not. The USDA’s Plant

protection Office has recorded over 500,000 introductions since 1898, mostly from outside the

United States, including large numbers of plants,

insects, and microbes. Although the proportion

that has actually become established is not known,

there have been occasional negative consequences,

sometimes severe or far-reaching. Few, however,

have been lasting, and fundamental ecosystem

processes and ecological relationships remain intact. Serious consequences have almost invariably been associated with introduced exotics. Table 1-4 summarizes some of the major differences

between planned introductions of genetically engineered organisms and exotics.

Most ecologists agree that successful introductions of exotic species, almost by definition, usually exert some effect, even though only a small

fraction of all introductions actually result in the

establishment and maintenance of a breeding population. Data for insects suggest that perhaps 41

percent of the species successfully introduced in

Table 1-4.—Comparison of Exotic Species and

Genetically Engineered Organisms

Exotic organismaEngineered organismb

No. of genes introduced 4,000 to >20,000 1 to 10

Evolutionary tuning All genes have Organism has several

evolved to work genes it may never

together in a have had before.

single package These genes will

often impose a

cost or burden

that will make the

organism less able

to compete with

those not carrying

the new genes,

Relationship of Foreign Familiar, with

organism to receiving possible exception

environment of new genes

a’ ‘Exotic organism’ IS used here to mean one not previously found m the habitat

b“Englneered organism’” IS used here 10 mean a sllghtly modlfled (usually, but nof always by

recombinant DNA techruques) form of an organism already present In the habitat

SOURCE Office of Technology Assessment 1988
18

the United States between 1640 and 1977 have

turned into minor pests, even though they had

no known detrimental effects in their original habitats. But not all species behave invasively when

introduced into a new habitat, and data on introductions are most likely to overestimate impacts,

given that organisms not producing an impact are

more likely to be overlooked. Experience with exotics suggests that introductions most likely to reSuit

●

●

●

in negative consequences include:

exotics introduced into an environment they

can colonize and where they have no potential natural predators or competitors, e.g.,

herbivores such as goats or rabbits introduced to an island;

ecological generalists or species that can survive and flourish on many different foods,

e.g., insects that can lay eggs on a variety of

host plants or parasites that include a wide

spectrum of species in their host range; and

exotics introduced into disturbed ecosystems

where natural relationships and constraints

have been disrupted.

Although no planned introductions actually reflect any of these scenarios, close analogs can be

found in agricultural systems, which are, in an

ecological sense, “disturbed. ” This may make agricultural systems seem especially susceptible to perturbations from unanticipated consequences of

a planned introduction. However, as noted earlier,

different strategies for managing agricultural systems provide many flexible control and mitigation

techniques. Furthermore, the better analogy with

experience from introduced agricultural varieties

provides additional reassurance.

Potential Impact on Populations

or Communities

Local populations or communities can be affected by the introduction of organisms (engineered or not) that are:

●

●

●

slightly modified forms of resident types,

forms existing naturally in the target environment but requiring continual supplements

to function,

forms existing naturally elsewhere that have

not previously reached the target environment, or

● genuine novelties.

Most anticipated introductions will be slightly

modified forms of resident types. Few are likely

to be forms existing previously in the target environment that require supplements, since the need

for continual supplementation of existing crops

(e.g., with fertilizers) is one of the forces impelling development of engineered varieties free of

such requirements. Forms existing elsewhere that

are new to the target environment bear the greatest similarity to exotic organisms, and thus carry

a higher risk of leading to problems. These also

promise great benefits, however, as with the introduction of predators to control introduced insect pests. Few genuine novelties are likely in the

foreseeable future.

Plant Communities

At present, most plant genetic engineering focuses on introducing into crop plants genes that

confer resistance to herbicides or pests, and these

alterations are technically among the easiest to

accomplish. The market for herbicides and pesticides is profitable and flexible. Modifying other

commercially important traits, such as yield components, overall protein production, taste, nutrition, or photosynthetic rates, lies farther in the

future.

A prominent concern is that herbicide-resistance

genes may spread into weedy relatives of crop

plants, most likely by sexual reproduction. If the

genes spread to weeds against which the herbicides are targeted, the herbicides become less effective. Such a development would most likely lead

to changes in herbicide use patterns or management practices.

One considerable genetic engineering effort

against a specific pest involves the insertion into

plants of genes coding for toxins from Bacillus

thuringiensis (BT). These bacterial compounds are

highly effective pesticides against the young larvae of butterflies, moths, and some beetles.

Farmers have applied BT to their fields in large

quantities for decades. Rohm & Haas (Philadelphia, PA) and Monsanto (St. Louis, MO) have already carried out successful field tests in which

engineered tobacco and tomato plants to which
19

BT toxin genes were added gained protection from

predation by caterpillars.

The simple presence of large quantities of BT

toxin in the environment is not worrisome because

it is not toxic to humans or animals, and it decomposes in a relatively short time. Produced inside

crop plant tissues, however, BT toxin is protected

from environmental degradation, thus extending

its persistence as it provides season-long pest control. However, this might introduce a problem of

a different kind: such an approach also lengthens

the time that less susceptible individuals (e.g., late

larvae and adults) of the target species may be

exposed to the toxin, and thus subjected to selective forces that can be expected to lead to evolution of resistance in those populations.

How severe this potential problem might be is

unclear. BT accounts for only a minor portion of

total pesticide use. While forestry and home garden use has increased in recent years, its market

share in agricultural use has declined, losing

ground to such promising new compounds as synthetic pyrethroids. But if the evolution of resistance to BT is judged to present more than just

a problem for product longevity, evolutionary biology offers several possible solutions.

Because resistance will most quickly evolve in

pest populations if the toxin is chronically present,

distribution of the toxin could be strictly limited

to the times and places it is needed. This could

be done by limiting the expression of the BT toxin

gene to those plant tissues that pest insects habitually forage on, or by inserting regulatory gene sequences that would induce expression of the BT

gene only in response to tissue damage caused

by the target pest. With progress in understanding gene regulation in plants, such measures may

soon be practical.

Another, immediately practical solution is based

on the observation that pathogens and pests adapt

more quickly to the defenses of prey species in

a genetically homogeneous community, such as a

cultivated field, than in a genetically diverse one.

Increasing the variation in the genes controlling

defenses against pests should slow the pests’ adaptive response. Genetically pest -resistant crop plants

could be mixed, for example, with unprotected

plants. A smaller proportion of protected plants

will exert lower selection pressures on the insect

populations, slowing their evolution of resistance.

Yet they would still offer enough protection to

preempt the growth of swarms of herbivorous

insects that cause the most crop damage. This approach is based on a strong theoretical and experimental foundation, and is well within the capability of existing technologies.

Insect Communities

Because they inflict so much damage on agricultural products, insect communities have become the target of recombinant plants, microorganisms, and insect predators engineered to

check them. Two representative examples are the

bacterium Pseudomonas fluorescent, which has

been altered to enable corn to resist the black cutworm, and a class of viruses that parasitizes certain pests.

The black cutworm feeds on the roots of corn

plants, causing significant corn crop losses. It is

vulnerable to BT toxin. Monsanto scientists have

used a special vehicle called a transposable element to insert the gene for BT toxin into Pseudomonas fluorescent, which lives among corn roots,

The transposable element has been altered to

make it unlikely that the inserted gene can move

beyond its insertion point or leave its Pseudomonas host. Preliminary tests suggest that the bacteria do not move beyond the roots they colonize

initially, nor are they likely to persist in a field

from season to season.

Baculoviruses, rod-shaped viruses that are specific pathogens to one or a few closely related insect species, are being developed to target insect

pests, including the cabbage looper and pine sawfly in the United Kingdom. Initial tests involved

inserting a marker DNA sequence into the virus

to enable scientists to track it. Researchers hope

this work will produce a better understanding—

and therefore better control—of the dispersal of

such altered viruses, as well as of the genetics of

host specificity.

Microbial Communities

Microbes can be and are being altered for many

uses. Two of the most useful potential applications involve altering root-inhabiting micro-
20

organisms to increase the amount of nitrogen they

fix (discussed later in this chapter), and inoculating plants with altered bacteria to enable them

to resist frost damage.

The introduction of ice-minus bacteria has been

a source of some controversy among the lay public (see ch. 3). The cell membrane of some bacteria contains a protein encoded by a single gene

that acts as an efficient nucleus for the formation

of ice crystals on the surfaces of plant leaves or

blossoms where the bacteria live. Without such

a nucleus, ice crystals do not form until about 9 ‘F

below freezing. Crop losses to frost damage in the

United States average about $1.6 billion per year.

Scientists reasoned that removing the ice-nucleating gene from the bacteria and using them to colonize crop plants could confer a measure of frost

resistance on the host plants and eliminate at least

a portion of the annual crop loss.

Small-scale field tests of this ice-minus system

present little risk: Ice-minus mutants are present

in natural bacterial populations. The different

strains produced by geneticists have precise

genetic alterations, unlike natural ice-minus bacteria, in which any of thousands of genetic changes

can produce the ice-minus trait. Nevertheless,

some observers of these fieldtests have been concerned about a possible worst-case scenario, albeit one that could only apply to large-scale uses

of ice-minus bacteria.

1 Natural precipitation depends on ice nuclei for

I

ice or water droplets to condense around and

grow big enough to fall as snow or rain. Terrestrial and marine plant material turn out to be more

effective than dust particles as ice nuclei, and bacteria growing on plant material may account for

a portion of this difference. If ice-minus bacteria

were widely applied in agriculture, some claim,

the atmospheric reservoir of ice nuclei might grow

smaller, changing local or perhaps even global

weather patterns. Some possible support for this

argument comes from Africa’s Sahel desert, where

overgrazing has reduced already sparse vegetation. In this scenario, the reduction in ice nuclei

due to overgrazing may have contributed, in turn,

to decreasing precipitation, further reducing vegetation.

Several different studies suggest, however, that

even under a long chain of worst-case assumptions (many of which contradict known facts) the

alteration of climatic patterns through large-scale

agricultural applications of ice minus bacteria is

not likely, Many of these assumptions, however,

could benefit from being tested by further research,

Potential Impact on Ecosystem

Processes

Ecosystems are enormously complex and, as a

rule, not well understood. Associations of plants,

animals, and micro-organisms interact with one

another and with their physical environment so

as to regulate the flow of energy through the system and the cycling of nutrients within it. The

major force driving these processes is capture of

the sun’s energy by photosynthetic plants and its

storage in biologically accessible carbon. Carbon

and all other substances vital to living things circulate within ecosystems in biogeochemical cycles. Any major perturbation of these cycles could

not only affect living organisms but might disrupt

the functioning of ecosystem processes. Much evidence, however, suggests that major perturbation

is unlikely.

All organisms require water, carbon, nitrogen,

oxygen, phosphorus, and sulfur; carbon and nitrogen are required in the largest amounts, and

are usually “rate-limiting.” When the biologically

available quantity of any of these substances sets

an upper limit on the living tissue (biomass) that

can be assembled from it and other components,

that substance is said to be limiting. When carbon is limiting, as it often is, it puts an absolute

upper limit on the biomass a habitat can support.

Plants are the primary carbon producers (fixers)

in most ecosystems, and decomposes such as insects, nematodes, bacteria, and fungi are the major movers of carbon once it has entered an ecosystem.

The nitrogen cycle (see figure l-l) is equally important, for plants require nitrogen to grow. Although elemental nitrogen is not limiting-indeed,

it makes up nearly 80 percent of the atmosphere

by volume–biologically accessible forms of it are.

Nitrogen fixation, a complex process that trans-
21

Figure 1-1 .-The Nitrogen Cycle

The nitrogen cycle: processes in terrestrial and aquatic systems. The microbially mediated processes include mineralization,

vitrification, denitrification, immobilization, and N-fixation.

SOURCE: Office of Technology Assessment, 19S8.

forms gaseous nitrogen into biologically accessible forms, is thus crucial to life on earth. The most

important nitrogen fixers are rhizobial bacteria,

those that live closely associated with the roots

of certain plants, particularly legumes.

Given the complexity of ecosystem associations,

interactions, and processes, it is not surprising

that introducing a genetically engineered organism into the environment has raised concerns. Perturbations of any of the fundamental processes

sketched above might have significant effects. Ecosystems, however, by the very complexity that

makes them difficult to understand, are buffered

and often resilient in the face of perturbations.

While fundamental disruptions of ecosystems

should be guarded against, historical experience with both accidental and intentional introductions suggests that such risks are not

likely consequences of any planned introductions of genetically engineered organisms be

ing considered now or likely in the near

future.

Nitrogen Fixation

Increasing the availability of nitrogen to economically important plants, thus increasing production per unit cost, would clearly benefit agriculure and forestry. But the biochemical

pathways of nitrogen fixation, which appear to

be similar in all rhizobial bacteria, are controlled

by multigene sequences. Research is under way

on these control mechanisms and on transferring

nitrogen fixation genes into plants themselves.

The symbiosis between nitrogen-fixing bacteria and their host plants is close. Nearly a century of experience with rhizobial inoculants demonstrates a lack of negative consequences from
22

introductions of such bacteria and makes this a

safe system to explore with field tests. Indeed,

larger changes to patterns of nitrogen distribution and movement in an ecosystem can generally be achieved by crop rotation than by microbial

inoculations.

Larger effects may be possible, however, if the

ability to fix nitrogen is transferred to nonleguminous plants. The technical complexity of

transferring the large number of genes involved

(about 17) and ensuring their effective control are

so great that this is not likely within 5 years, and

maybe not even in 10.

Microbes and Toxic Waste

Success in enhancing the ability of certain microbes to degrade toxic compounds, including her1 bicides, pesticides, and industrial wastes, could

make a major contribution toward alleviating today’s severe toxic waste problem. Naturally occurring microbes with such degradative powers are

being used increasingly to help cleanup environmental contaminants. On the other hand, introducing a microbe engineered to degrade several

classes of materials might conceivably lead to a

cascade effect—trigger a chain of consequences

arising from chemical similarities between some

toxic wastes and natural compounds. It is most

likely, however, that bacteria will be engineered

to deal with specific compounds, rather than diverse classes. However, if bacteria were engineered to clear up oil spills or grease deposits in

sewers, their potential to attack valuable resources

might be of concern. But in most microbial environments, carbon is severely limiting, and competition for it is intense. Competition with naturally occurring microbial populations would likely

be severe for most engineered microbes. The technical difficulty of producing such constructs

makes any associated potential problems unlikely

in the near future.

RISK ASSESSMENT

Most researchers and policymakers agree that

although there is no general methodology for predicting and evaluating the risks of planned introductions, a flexible, mechanism for review of those

that might pose some risk has, for the time being

(the next several years), much to recommend it.

It offers a high likelihood of anticipating potentially significant problems that might arise and

of revealing the kinds of planned introductions

that will merit the closest scrutiny as well as those

that might require little or none. Review procedures developed for assessing the risks of toxic

chemicals have been proposed as models, but it

is not clear how applicable these are. With many

commercial applications of biotechnology reaching the field-test stage, however, regulators need

clear risk assessment and risk management

guidelines.

An important element in approaching the current regulatory framework for regulating planned

introductions is to distinguish risk assessment

from risk management. Risk assessment is the use

of scientific data to estimate or predict the effects

of exposure to hazardous materials or situations;

the process may be qualitative or quantitative. Risk

management, on the other hand, is the process

of weighing policy alternatives to select the most

appropriate regulatory strategy or action. Risk

management depends on the scientific findings

of risk assessment, but also takes into account

technical, social, economic, and political concerns.

It is influenced by public opinion and requires

value judgments: How acceptable are the potential risks of genetically engineered organisms in

the environment relative to their benefits and the

costs of controlling them?

Must All planned Introductions

Be Reviewed?

Some scientists and public officials hold that

without an adequate, general database for risk

assessment of deliberate release experiments,

safety can best be ensured by comprehensive scientific review of all proposed releases case-by-case.

Others believe that some applications pose such

negligible risks that comprehensive review of

every proposed field test would be unnecessary

as well as burdensome. It is clear that not all

planned introductions offer the same potential for
23

undesirable consequences. It should be possible now, or become possible in the near future,

to sort planned introductions into broad categories for which low, medium, or high levels

of review are appropriate. All proposals for field

tests will require a certain, minimum level of scrutiny in order to assign them to one of these three

levels. What criteria can be used to determine

whether an application is inherently safe? Some

that are relevant include:

●

●

●

●

The engineered organism duplicates the

phenotype (appearance and function) and

community relationships of naturally occurring organisms or those produced with conventional methods.

The engineered organism will not survive and

reproduce after release into the environment.

The engineered genetic material will not be

transferred to any other organism.

The engineered genetic, physiological, and

ecological functions will have-no excessive adverse effects on the environment, or the effects will be unambiguously positive.

As more of the above conditions are met, the

level of review might be appropriately reduced.

More specific questions also need to be considered. Are there certain categories of organism that

are safer to release than others? Are there particular genetic alterations that pose fewer risks

than others? Some that have been suggested for

abbreviated review include:

●

●

●

organisms produced by recombinant DNA

techniques that are functionally identical to

organisms that could be produced by other

methods (e.g., mutagenesis and selection, or

hybridization) and, if so produced, would not

now be subject to regulation;

organisms containing no genetic material derived from any potential pathogen; or

any organism identical in function to one that

has already been reviewed and approved for

field testing.

Genetically engineered domesticated animals

and crop plants are widely (though not universally) considered to be relatively safe for release.

Given the relative containment of such introductions and the relative ease of controlling them,

review of introductions involving agricultural

plants and animals might well be kept separate

from reviews of introductions involving microbes.

Before assuming that a particular animal or plant

is safe, however, it is important to ask whether

the engineered trait would have any harmful potential in wild populations, and, if so, whether gene

flow to related natural populations is possible. The

latter will be tightly dependent on whether or not

the engineered plant or animal is closely related

to and can hybridize with any weedy or otherwise problematic species. In addition, animals or

plants that have been altered in a fundamental

metabolic function (e.g., a plant made capable of

fixing nitrogen) or are partners in mutualisms (interactions that benefit all species involved) also

require careful scrutiny.

Engineered organisms that are derivatives of

pathogens or pests, differing from the pathogen

or pest by only one or two gene changes or organisms engineered to receive from pathogens or

pests those genes that are associated with a destructive or disease process, constitute categories

likely to require extensive prior review. Most of

these are viruses, bacteria, or fungi whose virulence can sometimes shift via simple genetic

changes or in which a single gene can determine

the difference between a benign and harmful

form. Such potential pathogens and pests are unlikely to be exempted from review even though

here, too, most genetic changes can be expected

not to have effects of this sort. Considerable reassuring experience indicates that many pathogenic

organisms can be handled and tested safely (e.g.,

human and animal vaccines).

In another approach, the molecular details of

a genetically engineered organism could be examined to determine whether it could be exempted

from review. Such an examination should include

but

●

●

not be limited to these questions:

Does the introduced organism contain inserted genetic material from a donor of the

same genus, or from a different genus? A

slightly modified organism might be more

likely to persist in the environment into which

it was released, leading to greater potential

for long-term effects. It is also, however, more

likely to have occurred naturally.

Is the alteration an insertion or a deletion of
24

genetic material? Deletions generally present

less potential than insertions for long-term

survival of the organism, or reproduction, and

horizontal transfer of an introduced gene.

● Does the alteration involve a regulatory or

a structural gene(s)? Regulatory genes control the time, rate, and quantity of production of proteins encoded by structural genes.

Changing regulatory sequences could significantly alter an organism’s overall structure

or functioning, including its ability to survive

and reproduce.

In sum, although the characteristics of engineered organisms make certain kinds less likely

than others to cause problems, it is not now possible to describe any broad categories that could

be completely exempted from review. Counterexamples can be provided from existing experience to negate almost any proposed category for exemption from review. A review

procedure that involves the flexible, adaptable, case-by-case review of proposed planned

introductions deemed to involve significant

risk is most prudent at present. Such “case-bycase” language does not imply, however, that each

field test should be reviewed de novo. Experience

with reviewing proposals for planned introductions is rapidly being accumulated. It is reasonable to expect this experience will provide a data

base to justify establishing or broadening categories for abbreviated review, eventually to include

some exemptions.

Micro-Organisms v. Macro-Organisms

Ecological, genetic, and evolutionary impacts resulting from size differences among organisms

must be considered in assessing the risks of their

release. Particularly from ecological and evolutionary standpoints, microorganisms present

greater uncertainties than do macro-organisms,

though it is not clear this means they present

greater risks. Although most macro-orrganisms are

large, and thus relatively easy to track, many insects, weeds, and vertebrates that were introduced have been impossible to exterminate. Most

investigators agree that microbes are more difficult to track and control than macro-organisms,

though not all agree this means microbes pose

Charles Robert Darwin, 1809-1882. Discoverer of the

Principle of Natural Selection.

greater problems. On the other hand, the life history and population models now available to researchers often fit micro-orrganisms better than

macro-organisms, making them in some ways easier to study.

Although their large size means macro-organisms can move more biomass or cycle more nutrients through an ecosystem per individual than

micro-organisms can, they are not as numerous.

The rapid reproductive rates and easy dispersal

of small organisms could allow them to proliferate and spread faster through the environment

than large ones. And although micro-organisms

play key roles in fundamental ecosystem processes, functional redundancy among members of

microbial communities seems to provide a greater

degree of resilience to environmental perturbations than macro-organisms enjoy.

Evolutionary lability is an important consideration in biological risk assessment: Any assessment

of risks, no matter how thorough, would be inade-
25

quate should the engineered organisms evolve

traits they did not have when released. The potential for a population to evolve depends in part

on the numbers of individuals in that population,

but most importantly on the selective forces

involved. Therefore all reviews of planned introductions, particularly those involving microbes, should carefully scrutinze the selective forces that will be involved and the likely

consequences of selection on the introduced

organisms.

Implications for Research

Some of the controversies surrounding the initial attempts to release genetically engineered

organisms into the environment have pointed out

gaps in knowledge about ecological systems. Current and proposed small-scale field tests will

undoubtedly begin to fill some of these gaps and

contribute to the development of better risk assessment protocols, but more than this is needed.

Active research cooperation—intellectual, financial, and political—is vital.

Taxpayers are investing much to develop science and technology, but relatively little to develop

means for ensuring the safe and wise application

of such knowledge. Funding for science and technology, and the resulting research, is very uneven

across fields, The National Science Foundation and

the National Institutes of Health are major sources

for funding in biological research, but the basic

knowledge necessary to assess the performance

of a technology often remains undeveloped, even

as the technology is being refined for use. Research on the ways in which biotechnology may

influence natural and managed ecosystems, how

to assess its risks and benefits, and how to manage it as a technology, should perhaps be viewed

as part of the cost of developing the technology,

Research areas that need to be stressed include:

● test systems, such as aquatic and terrestrial

laboratory microcosms, where ecological interactions can be analyzed before actual release—although such tests are not sufficient

substitutes for field tests, they provide essential information needed in considering the potential consequences of planned introductions;

● the classification and relationships of organisms in natural populations (taxonomy and

systematic)) especially the genetic relationships of colonizing species or those organisms

related to candidates for engineering and

planned introductions;

● natural history of organisms planned for

genetic alteration and release;

. interactions within natural and managed

microbial communities (microbial ecology and

population dynamics); and

. more efficient and convenient monitoring and

tracking techniques for use in microbial

studies;

Interdisciplinary programs involving microbiologists, geneticists, ecologists, evolutionary and

molecular biologists, epidemiologists, and risk assessors managed by universities, industry, and

government agencies are critical to developing the

scientific foundation for setting adequate risk

assessment and risk management policies for biotechnology.

POLICY ISSUES AND OPTIONS FOR CONGRESSIONAL ACTION

Three policy issues related to the planned introduction of genetically engineered organisms

into the environment were identified during the

course of this study. The first involves the development of scientifically founded criteria for the

review of planned introductions of engineered

organisms. The second concerns actions that Congress might take to shape or direct regulatory policy toward the review and regulation of planned

introductions. The third relates to actions Congress might take to affect the development of information and trained personnel that will be

needed in the future to ensure that planned introductions continue to be carried out safely.

Following each policy issue several options for

congressional action are listed, ranging from taking no specific steps to taking major action. Some

of the options involve direct legislative action.

Others are oriented to the actions of the execu-
26

tive branch but involve congressional oversight

or direction. The order in which options are presented does not imply their priority. Furthermore,

the options are not, for the most part, mutually

exclusive: adopting one does not necessarily preclude adopting others in the same category or

within another category. A careful combination

of options might produce the most desirable

effects.

ISSUE: What criteria should be used to review

applications for permission to field test

planned introductions of genetically engineered organisms?

Scientists do not now agree that there is a clear

scientific need for a review process by different

mechanisms or according to different criteria for

engineered organisms intended for environmental

introduction than are now being applied to nonengineered organisms.

Option 1: An organism engineered for planned

introduction into the environment should not

require pre-release review simply because it

was produced via recombinant DNA techniques.

With this approach, planned introductions of

engineered organisms would not be reviewed

according to criteria or mechanisms any different than would be required for the same introduction if it did not involve an engineered organism. A review process organized in accord with

this option would have the advantage of focusing

exclusively on the product and its characteristics,

rather than the process used to produce it. This

approach could be most easily adapted to existing regulatory authorities and the mechanisms

through which they are administered. One disadvantage is that some potential problems associated with engineered organisms are different

than most of the problems existing regulatory authorities handle, e.g., problems stemming from

the ability of living organisms to grow, reproduce,

or transmit genetic material to nontarget species.

It is also possible that some engineered organisms

will raise significant, new questions that regulators would overlook, absent special review. However, such problems are not entirely new; some

are familiar, already regulated aspects of existing

practices, especially in agriculture. Nevertheless,

even if there is no clear need for a new regulatory approach, planned introductions of genetically engineered organisms could benefit from

some review at least for the foreseeable future,

even if only to provide public reassurance that

field tests of engineered organisms are not unduly hazardous.

Option 2: All proposals to introduce genetically

engineered organisms into the environment

should receive the maximum possible prerelease scrutiny.

The advantage of this approach is that it is most

likely to ensure that potential hazards associated

with field tests of any planned introduction will

be discovered and eliminated. The disadvantage

is that very few planned introductions, at least

for the foreseeable future, seem likely to present

significant hazards. Substantial resources could

be committed to unnecessary review; the personnel and resources of regulatory agencies would

be strained or swamped, and significant impediments would be placed in the path of researchers attempting to develop products.

Option 3: Planned introductions should be reviewed on an adaptable, case-by-case basis,

according to scientific criteria that are agreed

upon and consistent, and tailored to the specific questions posed by particular applications.

Any specific set of criteria is likely to be somewhat contentious. This will be especially true of

any criteria intended to apply to separate

proposals that would be reviewed by different

agencies. However, the broad outlines of a regulatory approach that should be generalizable are

clear: it should be possible to sort all applications for permission to field test engineered

organisms into broad categories for which

low, medium, or high levels of prior scrutiny

will be appropriate. Assigning an incoming application to a level of review must, of course, be

done on a case-by-case basis. This does not mean

that all applications for permission to field test

will require the same level of scrutiny: they should

not. Nor does it mean that the review of each application should begin de novo, without regard

to past experience with engineered organisms or

relevant knowledge gleaned from the study of

nonengineered organisms. Such background information is essential to expeditious review.
2 7

As experience accumulates, assuming no untoward developments, since the majority of planned

introductions are not expected to generate problems, the presumption of low level review might

be extended to a broader range of proposed field

tests. Conservative standards that could be useful in sorting proposals into the appropriate review category might include criteria like the following:

● Low Review:

—Product is functionally identical to one already reviewed and approved for field

testing.

—Product is functionally identical to others

that can be produced with nonrecombinant

DNA techniques.

—Product will entail lower levels of risk to

the environment or to public health than

existing products with which it will compete.

—Product differs from naturally occurring

organisms only by the addition of noncoding marker DNA sequences to noncoding

regions of the DNA of the recipient.

● Medium Review:

—Product is different in some ways, but generally similar to previously existing products in general use.

–Product entails substantial probability of

new genetic material being transmitted to

nontarget organisms in application environment or beyond.

—product entails significant probability of

altering community into which introduced.

● High Review:

—Product involves the transfer into a new

host organism of disease genes derived from

a pathogenic donor.

—Product is a genuine novelty with which

there is little or no previous experience that

can serve as a guide to risk assessment and

management.

–Product entails substantial probability of

disrupting community into which introduced.

ISSUE: What administrative mechanisms can

regulatory agencies use to apply such criteria to the review of applications for permission to field test planned introductions

of engineered organisms?

Option l: Allow regulatory agencies independently

to develop and apply criteria for reviewing applications for permission to field test planned

introductions of engineered organisms.

This would permit regulatory agencies to develop criteria for sorting and evaluating planned

introductions of engineered organism with exclusive attention to applications falling within their

separate jurisdictions (e.g., engineered plants by

USDA or engineered microbes by EPA). The

advantage to this approach is that agencies need

not consider issues that would be important only

to applications under the jurisdiction of another

agency. The drawback to this approach is that

different agencies might regulate according to disparate standards or criteria, leading to inconsistent levels of review, regulation, or enforcement.

Option 2: Direct the regulatory agencies to develop, in coordination with one another, but

not by any particular process, specific criteria

for classifying and reviewing applications for

permission to field test planned introductions

of engineered organisms.

This was the original intent of the Coordinated

Framework established by the Administration on

June 26, 1986 (51 Fed. Reg. 23301). In order for

this option to function well, however, effective

leadership is needed from a coordinating authority. Under the Coordinated Framework, it was intended that this role be fulfilled by the Biotechnology Science Coordinating Committee (BSCC). As it

is presently constituted, the BSCC lacks the power

to impose its decisions upon the regulatory agencies, or to eliminate disparities in approach by

different agencies. Criteria for review that have

emerged under this framework to date have not

been entirely consistent among agencies. In addition, basic tasks, such as the adoption of commonly

agreed upon definitions for “deliberate release)”

have not yet been accomplished.

Option 3: Provide an interagency group with the

power to direct the coordinated development of

criteria for classifying and reviewing applications for permission to field test planned introductions of genetically engineered organisms.

This would produce a system similar to that embodied in the Biotechnology Science Coordinat-
28

ing Committee and outlined in the Coordinated

Framework, except that the coordinating body

would be created by Congress and would have

specific powers. Such a body, created by Congress,

could be composed of the same or different members as the BSCC, organized within the Office of

Science and Technology Policy, or created elsewhere. It would have the authority to direct the

preparation of review standards to be used by

regulatory agencies according to consistent criteria, and to standardize regulatory approaches

as much as possible among different agencies. It

could develop such standards independently or

in conjunction with the relevant agencies.

ISSUE: Is research supporting the planned introduction of genetically engineered organisms adequate?

Option 1: Take no action.

A significant amount of research is now funded

by the Federal Government in areas that contribute to the knowledge base required for sound review and regulation. Principal agencies now sponsoring or conducting such research are NSF, NIH,

USDA, and EPA. Such research will likely continue

in the absence of additional, targeted appropriations. An example of the type of research likely

to be productive is the recent OSTP sponsored

initiative, jointly funded by NSF, USDA, and DOE,

to fund interdisciplinary, fundamental research

in several targeted areas of plant science.

Option Z: Establish an interagency task force to

coordinate interdisciplinary research.

Whether or not funding is increased, the different agencies funding relevant research (NSF,

USDA, NIH, and DOE) could increase their coordination in the sponsoring of new research initiatives. The recent collaboration between NSF, DOE,

and USDA in the establishment of an initiative for

research in plant science might be an appropriate model.

Option 3: Increase research funding to selected

target areas.

If funding is increased to selected areas, it could

most profitably be directed to the divisions of funding agencies sponsoring most of the relevant research. These include, at NSF, the Directorate for

Biological, Behavioral, and Social Sciences, and its

components, the divisions of molecular biosciences, biotic systems and resources, information science and technology, and others; the National Institute of Environmental Health Sciences

and the National Institute of General Medical Sciences at NIH; components of the Division of Science and Education at USDA; and at DOE, the Of -

fice of Health and Environmental Research in the

Office of Energy Research.

Particular value is likely to be derived from

funding earmarked for interdisciplinary studies,

or collaborations between scientists in the various disciplines important to understanding and

predicting the consequences of environmental

perturbations. Emphasis should be given to

studies focusing on the single most important

factor affecting the fate and consequences of

planned introductions: natural selection, o r

the selective interactions between competing

organisms, and the selective pressures on organisms due to environmental factors. Other promising areas include basic research in molecular

and developmental biology, studies of gene regulation, microbial ecology, community interactions

and processes, and evolutionary and ecological

relationships.

The disadvantage of such targeting is that it assumes the specific areas where the most important research should be done can be accurately

predicted. The results of research are, by nature,

unpredictable; this may be especially true of the

interdisciplinary research important to planned introductions. Administrative flexibility and adapt -

ability would therefore be important in any such

programs, along with the avoidance of undue

specificity in the targeting of funds.

Risk assessment and management are vital areas

that will increase in importance with the numbers of planned introductions. They lack, however, a strong, vocal constituency to argue for increased funds. The primary agency now funding

such studies is EPA, and much of the sponsored

research is applied in nature. Both EPA and NSF

could be encouraged to enhance their support for

basic research relevant to biotechnology research

assessment. In the absence of a strong, organized,

vocal constituency to help advise on the most

effective program, progress might be driven by
29

allocating for risk assessment and management

research a fixed proportion of the funding designated for research in other relevant areas.

Public education specific to biotechnology is

another important area presently lacking a strong

constituency to argue for improvements. They

could be achieved through actions taken by the

Science Education divisions of both NSF and USDA.

Specific measures might include brochures and

pamphlets, newsletters, public conferences and

debates, yearbooks and annual reports, and extension service activities.

Option 4: Increase personnel education and

training.

Because they already have similar programs, the

primary agencies to administer any new training

programs would logically be NSF, NIH, and USDA.

For the near future, the most effective investment

would be in programs to provide mid-career training for established investigators. Other valuable

programs could include funds for graduate student and postdoctoral training.

There is an urgent need for scientists who are

neither molecular biologists nor ecologists, but

investigators comfortable with and competent in

the techniques and background knowledge of both

areas, able to use whichever tools are appropriate to the task. Interdisciplinary training is vitally

important to the production of such investigators.

Part of the reason there is not more research now

being done to develop methods of predictive ecology and risk assessment has to do with historical

neglect of these areas by funding agencies, since

recognition of their importance has been slow to

emerge, But as funding availability has increased

in the recent past there has been a relative shortage of investigators applying for or trained to carry

out such research.
Chapter 2

Introduction

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Chapter 2

Introduction

This report addresses some of the genetic and

ecological questions raised by the planned introduction of genetically engineered organisms. This

introductory chapter provides a context for the

report’s more technical material by recounting

the historical background of the issue and reviewing the types of planned introductions either proposed by industry or otherwise likely in the near

future.

Of the many consequences of the commercial

development of biotechnology, the most far-

-reaching will likely result from environmental applications of genetically engineered organisms, if

only because their sites of application will often

be agricultural lands and products. Commonly

called “deliberate release, ” planned introductions

of these altered organisms may increase agricultural productivity, aid in the cleanup of toxic

wastes, enhance the recovery of minerals from

low-grade ores in mining, and provide new applications or enhancements of many existing processes. (The term “planned introduction” will generally be used in this report; other synonyms

include: intentional release, deliberate release, free

release, and environmental application.)

Some observers, however, warn of the potential for damage through unanticipated consequences of a planned introduction. Although the

probability of something going awry maybe very

small in any individual case, the possibility of substantial environmental impact if something should

go wrong is not trivial (7,16,19). The world’s experience with unanticipated problems related to

the petrochemical and nuclear power industries

plus recent concerns about disruption of global

processes by acid precipitation (22), increased levels of atmospheric carbon dioxide (2,10,12), and

other results of chronic environmental alteration

suggest such cautionary voices should be listened

to. Yet the real similarities between such analogies and biotechnology are scant, and fear should

not substitute for reasoned discourse on the potential costs and benefits of a new technology.

Chapter 3 outlines the existing mechanism for

regulating planned introductions, and discusses

the role of public opinion in shaping regulatory

policy. It also describes the experiences of a number of the communities in which early field tests

have been proposed, completed, or planned, and

recapitulates some relevant results of an OTAcommissioned survey by Louis Harris & Associates (26).

Chapters 4 and 5 summarize and synthesize information on some of the potential consequences

of planned introductions of genetically engineered

organisms, and the problems that face regulators

in estimating the likelihood of such consequences.

Chapter 6 discusses risk assessment issues, identifying present capabilities and future needs that

must be met to improve risk assessment. A number of technical contract reports were commissioned in support of this study; their titles are given

in appendix C.

The potential benefits of biotechnology in general, and of planned introductions of genetically

engineered organisms in particular, are widely

recognized and described in other studies (4,14,

15). Some sense of this potential may be gleaned

from appendix A and table 1-1. This report examines hypothetical negative consequences of such

applications. In doing so, OTA seeks to establish

whether there are areas of potential concern that

might be addressed by legislation that would mandate the assessment and management of planned

introductions. Most of the possible negative impacts described are more relevant to perturbations of natural ecosystems than to perturbations

of the agricultural systems that will host the

majority of imminent environmental applications.

As such, negative impacts are not likely to be common consequences of planned introductions in

the foreseeable future.

In focusing primarily on questions of potential

risk, this report leaves a number of important issues unexamined:

the economics of research and development

(R&D) of planned introductions of genetically

engineered organisms;

the economics of different regulatory ap33
3 4

preaches;

the relationship between R&D and regulation;

and

the potential for social changes and economic

rearrangements, as well as a broad range of

ethical questions and occupational safety considerations.

Some of these issues are examined in other reports, and it is not clear that biotechnology raises

unique questions in these areas.

Developing engineered organisms for specific

environmental applications is unlikely to be as expensive as developing a broad-spectrum chemical pesticide, which may cost as much as $50

million (to which regulatory costs contribute significantly). But because the introduction of an engineered organism is likely to be more precise and

limited than that of a chemical pesticide-indeed,

this is perceived by some as one of the advantages

of such engineered organisms—the market over

which to amortize the costs of R&D and regulation is small. If the costs of regulating engineered

organisms are too high, the development of some

applications may be economically unrewarding.

It would be ironic if concerns over the

potential impacts of planned introductions,

which may be safer than the competing chemical technologies they could displace, lead to

such astringent and expensive regulatory appreach that economics forced continued reliance on older, less safe technologies% But if

risks sufficient to justify restrictive regulation

are identified, it would be logical to extend restraints to existing technologies that entail

similar or higher risks.

And while the following chapters suggest that

a regulatory system is not strongly grounded in

science if it places primary importance on the

processes used (e.g., recombinant DNA techniques)

rather than the product produced, it cannot be

shown that such an approach is entirely without

foundation. It is generally agreed that the new

techniques will make it possible to do much more

quickly many things that were possible before,

but only over substantially longer periods. In addition, the new techniques will make it possible to

do some things, such as moving genetic material

between very different organisms, that would previously not have been contemplated. It will be the

challenging task of those who assess and manage

risk to determine if these new techniques will

eventually bring with them any qualitatively new

risks, although it is not now clear that they will.

It is also true that environmental applications

of engineered organisms, by increasing yields or

productivity in agriculture, may significantly affect economic or social patterns (something that

is already taking place independently of biotechnology). Pesticide or herbicide use may be redirected. Growing ranges and seasons of specific

crops may shift. Production of specific crops may

increase or decrease. The problems and advantages of monoculture and crop diversity may

grow or decline. Some of these questions have

been studied (25), but none has been approached

from the standpoint of genetically engineered

organisms in new environmental applications. All

these issues could profit from closer examination

than is within the scope of this report.

HISTORICAL CONTEXT

Agricultural biotechnology can be traced, some

claim, to the earliest domestication of plants and

animals in the Middle East, as long as 10,000 years

ago (20). Industrial biotechnology is considered

by some to follow the prehistoric development

of wine making, or the development of brewing

in the 11th century. Others see biotechnology dating from the discovery of the structure of deoxyribonucleic acid (DNA) in 1953. Still others date

modern biotechnology from the early 1970s, when

the tools (restriction enzymes) to move specific

pieces of DNA within and between organisms with

precision were discovered. These tools greatly increased researchers’ ability to intervene in the

hereditary processes of plants, animals, and microorganisms. Some individuals see this increase as

both a quantitative and qualitative change, affecting not only the amount of intervention possible,
35

but also the kind of effects that can be produced.

Regardless of the date chosen as the dawn of biotechnology, the new genetic engineering techniques open possibilities unimagined as recently

as two decades ago.

The development of modern biotechnology began, predictably, in research laboratories, where

scientists used the techniques to study the structure, function, and organization of genetic material. As technology improved, it became possible

to investigate increasingly precise questions about

the function of physiological systems and the regulation and interactions of biochemical pathways.

Eventually, work with the powerful new tools

turned naturally to practical applications, giving

rise to the commercialization of biotechnology,

a subject examined in an earlier OTA study (23).

The broad applicability of the new techniques

is illustrated in the range of industries affected

by the emerging biotechnologies. The pharmaceutical industry felt the earliest large effects, with

the newly acquired ability to produce significant

amounts of such rare or difficult-to-isolate compounds as human growth hormone, insulin, and

compounds to dissolve blood clots. Logical extensions of these technologies may result, eventually,

in the repair of defective genes in living individuals to cure or ameliorate human genetic diseases

(24). The use of monoclinal antibodies (a biotechnology which does not involve recombinant DNA)

is expected to revolutionize the diagnosis and treatment of some forms of cancer.

Areas such as specialty chemicals, food additives, commodity chemicals, food processing,

waste disposal, mining, and energy production will

also experience the effects of biotechnology.

Molecular biology and microelectronics may one

day meet in a powerful fusion and synthesis,

thanks to the new techniques. But agriculture is

the next area likely to feel dramatic impacts from

biotechnology. Many of these impacts will result

from the planned introductions of organisms

(mainly plants and microbes) genetically modified

to serve precise purposes.

Some observers of these new applications foresee the environmental use of organisms tailored

to perform a host of functions. They envision the

production of plants that will resist insect pests,

disease, and drought; make their own fertilizer;

or use nutrients or energy more efficiently. They

point to microbes altered to protect crops from

frost damage or insect pests; to metabolize toxic

wastes contaminating soil or sludge; or to extract

rare minerals or compounds more efficiently.

Others point out that we know so little about

how our environment actually functions, of how

its components interact (or sometimes, even, what

those components are), that it is difficult if not

impossible to produce a comprehensive, quantitative assessment of the potential risks to the environment from a particular introduction. They dispute the lowest risk estimates of the strongest

proponents, and claim that the closest analog to

experience with deliberately introducing genetically engineered organisms into the environment

is the introduction of exotic plant or animal species into habitats where they were previously unknown. Although more such introductions have

been beneficial, or neutral, than harmful, the

European starling, gypsy moth, kudzu, Russian

thistle (tumbleweed), and cheat grass are wellknown examples of negative consequences that

can follow when new species are introduced into

environments lacking natural checks. If planned

introductions could cause similar problems, then

potential ecological effects must be scrutinized

closely (see ch. 5).

An examination of the pending and potential

planned introductions of genetically engineered

organisms suggests, however, that in most cases

engineered organisms are not new to the environment in which they will be used. Almost invariably, either the same organisms or very close

relatives already exist in the ecosystem where the

proposed application would take place. The major difference between the existing and introduced

organisms lies in the addition or alteration of a

specific gene or set of genes regulating some aspect

of a biochemical pathway.

Instead of likening deliberate release to the

introduction of organisms into a new environment, a more reasonable comparison might be

the entrance of new genes into existing organisms. There is a long history of selective breeding in plants, animals, and microbes, much of it
36

carried out with no specific knowledge of the drastically negative. These reassuring points were ‘

mechanisms of heredity or the nature of the also cited in a recent paper by the National Acad -

hereditary material. Selective breeding has pro- emy of Sciences (13). But it remains true that most

duced organisms that have surely changed envi- cases of severe environmental trauma seem to

ronments and ecosystems, but few that are gen- have been the logical consequences of intentional

erally agreed to have been deleterious, much less activities initially felt to have been unrelated to

ruinous. Fewer still have been both runaway and their eventual effects.

PENDING AND POTENTIAL ENVIRONMENTAL APPLICATIONS

OF GENETICALLY ENGINEERED ORGANISMS

How can the potential environmental effects

from planned introductions be anticipated? Perhaps by considering the nature and range of a

representative sample of anticipated applications.

Even the cursory review in this chapter of the

pending and potential planned introductions of

genetically engineered organisms illustrates that

most areas of human life will be touched by these

new technologies. (These applications are also referred to throughout the report in the discussions

of issues in ecology and genetics that might be

of concern.) Microbes, plants, and animals all stand

to be affected directly. Most of the pending or

potentially near-term applications involve minor

alterations to enhance an existing capability or

function. Those that do impart genuinely new capabilities are few in number, but even these are

fairly simple or straightforward. Most are controlled by only one structural (i.e., proteinproducing) gene.

Plants

Applications of genetically altered plants could

be numerous and early, and among the least contentious because plant dispersal is comparatively

easy to monitor. The genetic changes being made

to plants are constrained primarily by technological difficulties peculiar to plants: the relative paucity of methods for inserting DNA, and the peculiar requirements for culturing different plant cell

lines. Despite these constraints, numerous companies and researchers are making progress (see

app. A).

Genes have been introduced into numerous

plant species to confer resistance to herbicides

including glyphosate, atrazine, phosphonitricin,

the sulfonylureas, and imidazolinones. Some field

tests have already been concluded. Other, similar work has transformed different crop plants

with genes conferring resistance to one or another

antibiotic, a genetic tag that makes the engineered

plants easier to monitor.

In addition to herbicide resistance genes, disease resistance genes have been used to transform

tobacco plants. The first field tests of plants made

resistant to crown gall disease were carried out

in 1986.

In a related development, a long known (but incompletely understood) phenomenon has been exploited to provide protection against some plant

viral infections. Plants inoculated with mild strains

of certain viruses or viroids acquire some protection from more virulent strains that cause severe

disease. A collaborative effort between researchers at Washington University in St. Louis, MO,

and Monsanto Co. has resulted in this “cross protection” against tobacco mosaic virus being engineered into tobacco plants. In that work, a single

viral gene encoding a viral coat protein was inserted into the plant genome. Preliminary indications suggest that the same process might be useful in protecting other plants against a variety of

viral diseases.

Many other genetic manipulations to tailor

plants for specific environmental applications are

being pursued now, or are likely to be pursued

in the future. Tolerance to drought, irrigation

water salinity, extremes of temperature, and variation in soil conditions all are subject to different degrees of genetic control, making them susceptible to directed manipulations. Because plants

engineered for increased tolerance to these fac-
3 7

Photo credit: Rohm & Haas Co.

Manduca sexta (tobacco hornworm) larva at work. The

moth will consume 95 percent of its entire life cycle’s

food supply while in the larval stage of development.

Moth larvae are the most destructive insects to world

agriculture and forestry.

tors maybe grown in habitats new to them, some

of the precautions taken to assess the risks of introducing exotic species may apply. Researchers

also report substantial progress in the development of recombinant DNA techniques to alter or

improve the nutrient qualities of crop plants (9).

Researchers may also explore the possibility of

increasing the concentrations of “antifeedants” in

seeds. Such compounds (e.g., canavanine), toxic

to seed-eating insects, occur naturally in some

seeds. Their production is under genetic control,

and concentrations vary in seeds from different

plant populations and species. This natural variation has already been exploited to reduce losses

Photo credit: Monsanto Co.

Monsanto and Washington University researchers

begin field test of tomato plants carrying BT toxin gene

in test plot in Jersey County, Illinois, summer of 1987.

Examining experimental plants in foreground are

Robert Fraley, Director, Plant Science Technology,

Monsanto Co., and Roger Beachy, Professor of Biology,

Washington University in St. Louis, Missouri.
38

from insects, particularly in some developing

countries. It would be relatively simple to transfer the capacity for producing such compounds

to plants that are not naturally able to protect their

seeds in this way. Care must be taken, however,

that such added compounds do not have negative consequences for the intended consumer, as

are known with brown sorghum (6).

In the future, scientists maybe able to alter nonleguminous plants to enable them to extract usable nitrogen from the atmosphere (to ‘(fix” nitrogen). However, the technical problems associated

with transferring this capability are greater than

those posed by almost any of the other applications so far mentioned. While most of those applications involve a single gene, or at most a small

number of genes, nitrogen fixation involves as

many as 17 different structural genes with associated regulatory elements. To transfer such a

gene complex from the parent bacterium into a

plant and ensure its proper function in the new

genetic background is a challenging task beyond

the reach of present techniques. Studies of plant

gene regulation are progressing, however. And

the first plants with symbiotic bacteria engineered

to increase their fixation of nitrogen were ready

for testing in 1987, and slated for field tests in

1988.

Other, more tractable plant applications involve

the genetic engineering of marine algae to increase

their production of food additives (carrageenan,

betazarotene, and agar). Someday algae may even

be altered to sequester rare minerals or metals

found dissolved in sea water, providing an intriguing fusion of the agriculture and mining industries.

Animals

Because animals are generally larger than microbes, and relatively easy to track, animal applications of genetic engineering have met with less

controversy. Most biotechnology work aimed at

animals is focused on veterinary products for animals, such as vaccines, or on hormonal supplements like bovine somatotropin. Much of the work

that is directed at altering animal genomes per

se is geared toward altering farm stock to improve

reproductive performance, weight gain, disease

resistance, or coat characteristics. Since such

organisms (indeed, and many crops, as well) will

be restricted to agricultural settings, it will often

make more sense to consider them “contained”,

rather than as introduced into the environment

in the way that microbes are. Work is also being

done to develop cattle or sheep as ‘(factories” for

such substances as human blood factor IX, and

other pharmaceuticals.

In work that may be relevant, researchers in

Michigan and in Washington are developing

strains of fish (salmon) that should live longer and

grow larger than average. The procedure involves

exposing early fish embryos to abnormally high

temperatures. The ensuing shock causes a peculiar chromosomal abnormality (a doubling of one

of the chromosomal sets, a condition called

triploidy) that disrupts the fish’s normal sexual

development. The results include infertility as well

as longevity and increased size. The altered fish

avoid the usual fate of spawning followed by

death. Sterile, triploid grass carp are produced

in a similar manner, and being used to control

some aquatic weeds in Florida. Other researchers (primarily in foreign countries) are working

to introduce specific genes into different fish species to increase temperature tolerances or growth

rates. Because fish engineered for increased tolerance to such environmental stresses may thrive

in habitats new to them, some of the precautions

taken to assess the risks of introducing exotic species may apply.

Microbes

Genetically engineered microbes present more

uncertainties and generate more concern and opposition than engineered plants or animals. Their

small size complicates the task of monitoring and

tracking dispersed microbes (5). The genetic promiscuity of some microbes also makes horizontal

transfer of genetic material more likely. And microbes are involved inmost fundamental ecological processes. But this same involvement, together

with the ubiquity of microbes, makes them the

choice for many environmental applications of genetically engineered organisms contemplated at

present. An enormous amount of past experience with microbes introduced for biocontrol

or agricultural purposes suggests that most in-
39

productions of engineered micro-organisms

are likely to be without noticeable ecological

consequence% Although most such introductions can be expected to be safe, a few instances

of problems with biocontrol microbes used in agriculture suggest the need for some caution (17).

Bacteria are being studied for a host of innovative pesticidal applications. Of great interest is

Bacillus thuringiensis (BT), a bacterium that produces a protein that is toxic to the larvae of many

Lepidoptera (butterflies and moths); different

strains produce proteins toxic to some other insect pests, primarily some flies and beetles. A protein known as the delta-endotoxin is produced by

a gene that has been inserted into a bacterium

(Pseudomas fluorescens) that lives on the roots

of corn plants. Scientists hope this will protect

corn crops against losses to the black cutworm,

which can be substantial in infested fields. Other

researchers have inserted the same BT gene directly into plants to exploit its pesticidal properties. In yet another application, the gene has been

inserted into a different bacterium that is then

killed and preserved in a novel way to increase

the toxin’s persistence. Under normal circumstances, the ultraviolet-light-sensitive toxin degrades very quickly in the environment; by protecting it from ultraviolet light inside the killed

bacterium, the toxin’s efficacy as a pesticide is extended.

Viruses also offer potential for exploitation as

pesticides. In particular, different baculoviruses

(so named for their rod-like shapes) are specific

for many insect pests. Genetic engineering to enhance their virulence and limit or alter their host

ranges promises to increase their usefulness (2 I).

Early applications of viruses that are pathogenic

to insect pests of cabbage plants or pine trees are

at or near the field test stage in the United Kingdom, where larvae are serious pests to agriculture and forestry. Research is being carried out

on similar systems in several universities and industrial laboratories in the United States.

Other viral applications involve the production

of vaccines for both animals and humans. Separate research programs are aimed at tailoring the

vaccinia virus to produce vaccines against such

diseases. A recombinant vaccine has already been

developed for hepatitis B, a major Third World

health problem. Other vaccines are being developed for herpes simplex, influenza, hookworm,

and AIDS (acquired immunodeficiency syndrome).

Animal applications under development include

vaccines for vesicular stomatitis (cattle), swine

pseudorabies, mammalian rabies, and others.

Some of these animal vaccines have undergone

field tests, which have generated varying degrees

of controversy (see ch. 3).

A number of different groups in the United

States and Europe are working on multivalent vaccines designed to protect against several diseases

with one vaccination, or against one disease that

is antigenically complex (e.g., malaria, sleeping

sickness, or schistosomiasis). These programs aim

to exploit the large capacity of the vaccinia virus

to carry genetic information. This large capacity

enables the virus to carry several genes encoding

different proteins that will each stimulate an immune response. One of the difficulties in developing vaccines for antigenically complex diseases

has been the different antigens the disease agents

express at different stages of their life cycles.

Traditional vaccines may stimulate an immune response that will protect against infection at one

stage in the parasite life cycle, but not another.

Vaccinia-based vaccines may overcome this obstacle. Clinical experience with traditional vaccines

against many virulent diseases gives excellent reason to suppose that engineered vaccines will be

at least as powerful and safe.

Bacteria are also being genetically altered to

metabolize specific toxic compounds found in

waste or industrial sludge. In recently reported

work, scientists have tailored metabolic pathways

in bacteria to enhance their ability to metabolize:

benzene derivatives (18); the halogenated hydrocarbons (polychlorinated and polybrominated

byphenyls (PCBs and PBBs), and dioxin); and oil

spills (3)8). The past 5 years have seen much significant progress in this area, using enrichment

cultures and naturally occurring bacteria that are

then applied to environmental problems. Many

naturally occurring bacteria can degrade complex

organic compounds, and some are being harnessed to keep closed ecosystems clean, as in the

soil bed reactors planned for Biosphere II (1) or
40

in wastewater treatment facilities that must cope

with activated sludge.

“Ice-minus” bacteria, the altered bacteria for

which the first field test permission was requested,

have received the most publicity. These bacteria

are expected to reduce frost damage to crops, a

problem that costs U.S. agriculture an estimated

$1.6 billion annually. Ice-minus bacteria differ

from unaltered bacteria in that a single gene has

been deleted, one that normally encodes specifications for the construction of a protein normally found in the cell membrane. This protein

acts as a potent nucleator for the formation of

ice crystals. In the absence of such a nucleator,

ice does not commonly form until the temperature drops 5 to 10 “F below freezing. Researchers at the University of California at Berkeley, and

at Advanced Genetic Sciences in nearby Oakland,

reasoned that the gene for this ice-nucleating protein could be deleted from the bacteria. These

altered bacteria—virtually identical to bacteria that

can be found in nature-could then replace the

normal, ice-nucleation positive (INA +) bacteria

living on the leaf surfaces of crop plants, thus providing some protection to frost-sensitive crops.

Collaborative work between these groups of researchers has produced early systems designed

to protect such crop plants as potatoes and strawberries. Successful field tests of both were conducted in 1987.

An important new marker system called “lac ZY”

is being developed to track engineered microbes

in the environment. Researchers from Monsanto

Co. and Clemson University are developing the

system through a collaborative effort (11).

SUMMARY

Planned introductions of genetically engineered are difficulties in estimating precisely the potenorganisms span an enormous range in terms of tial environmental hazards, and in assessing the

the altered organisms, the diverse environments risks and benefits for any particular application.

in which they are to be applied, and the types of But there is also a substantial body of relevant

functions they are intended to perform. There experience that can be used as a guide.

CHAPTER 2 REFERENCES

1. Allen, J., and Nelson, M,, Space Biospheres (Oracle, AZ: Synergetic Press, Inc., 1986).

2. Broecker, W. S., “Unpleasant Surprises in the

Greenhouse?” Nature 328:123-6, 1987,

3. Chakrabarty, A.M. (cd.), Biodegradation and Detoxification of Environmental Pollutants (Boca Raton, FL: CRC Press, Inc., 1982).

4. Crocomo, O.J., Sharp, W.R., Evans, D.A., et al. (eds.),

Biotechnology of Plants and Microorganisms (Columbus, OH: Ohio State University Press, 1986).

5. Gillett, J.W. (cd.), Prospects for Physical and BioIo@”cal Containment of Genetically En@”neered

Organisms (Ithaca, NY: Ecosystems Research Center Report 114, March 1987).

6. Hahn, D. H., Rooney, L.W., and Earp, C. F,, “Tannins and Phenols of Sorghum,” Cereal Foods World

29:776-779, 1984.

7. Halvorson, H.O., Pramer, D., and Rogul, M., En@”-

neered Organisms in the Environment: Scientific

Issues (Washington, DC: American Society for

Microbiology, 1985).

8. Johnston, J.B., and Robinson, S.G., Genetic En@”-

94

10.

11,

12.

13.

14.

neering and New Pollution Control Technolo@es

(Park Ridge, NJ: Noyes Publications, 1984).

Jones, M. G. K., “Plant Genetics: Transformation of

Cereal Crops by Direct Gene Transfer,” Nature

317:579-580, 1985.

Mathews, J.T., “Global Climate Change: Toward a

Greenhouse Policy,” Issues in Science & Technol0~ 3:57-68, 1987.

Marx, J. L., “Assessing the Risks of Microbial Release,” Science 237:1413-1417, 1987.

Mintzer, I., “A Matter of Degrees: The Potential for

Controlling the Greenhouse Effect,” Research Report #5, World Resources Institute, Washington,

DC, April 1987.

National Academy of Sciences, Introduction of Recombinant DNA-En#”neered Organisms Into the

Environment: Key Issues (Washington, DC: National Academy Press, 1987).

National Research Council, Agricultural Biotechnology: Strate@”es for National Competitiveness (Wash-
ington, DC: National Academy Press, 1987).

15. Olson, S., Biotechnology: ArI lndmtry Comes of Age

(Washington, DC: National Academy Press, 1986).

16. Panem, S. (cd.), BiotechnoZo~:Implications for PubZic Policy (Washington, DC: The Brookings Institute,

1985).

17. Pimentel, D., Gleniston, C., Fast, S., et al., “Environmental Risks of Biological Pest Controls, ” Oikos

42:283-290, 1984.

18. Ramos, J. L., Wasserfallen, A., Rose, K., et al.,

“Redesigning Metabolic Routes: Manipulation of

TOL Plasmid Pathway for Catabolism of Alk~lben -

zoates, ” Science 235(4788):593-596, 1987.

19. Regal, P. J., “Models of Genetically Engineered

Organisms and Their Ecological Impact ,“ EcoZogV

of Biological Int~asions of North America and Hawaii, H.A. Mooney and J.A. Drake (eds. ) (New York,

NY: Springer-Verlag, 1986).

20. Stubbe, H., Historuy of Genetics from Prehistoric

Times to the Rediscovery of Mendel’s Laivs (Cambridge, MA: MIT Press, 1972).

21. Summers, M. D., and Smith, G. E., “Genetic Engineering of the Genome of the Autograph California Nuclear Polyhedrosis Virus, ” Genetically Altered Viruses and the Environment, B. Fields, Itl .A. Martin,

and D. Kamely (eds. ), Banbury Report No. 22 (JNe\v

York, NY: Cold Spring Harbor Laboratory, 1985).

22. U.S. Congress, Office of Technology Assessment,

Acid Rain and Transported Air Pollutants: Implications for Public Policy, OTA-O-204 (Washington,

DC: U.S. Government Printing Office, June 1984).

23. U.S. Congress, Office of Technology Assessment,

Commercial Biotechnology: An International Analysis (Elnlsford, NY: Pergamon Press, Inc., 1984).

24. U.S. Congress, Office of Technology Assessment,

Human Gene Therapy, OTA-BP-BA-32 (Jf’ashington,

DC: U.S. Government Printing Office, December

1984).

25. U.S. Congress, Office of Technolo&v Assessment,

Technology, Public Policy, and the Changing Structure of American Agriculture, OTA-F-285 (Washington, DC: U.S. Government Printing Office,

March 1986).

26. U.S. Congress, Office of Technology Assessment,

New Developments in Biotechnology, 2: public Perceptions of Biotechnology, OTA-BP-BA-45 (Washington, DC: U.S. Government Printing Office, May

1987).

.. .$*...*.....!.@****. *

-------- -
Chapter 3

The Role of Public Perception

and the Regulatory Regime

Field tests involving the deliberate release of genetically engineered organisms into the environment have resulted in increased public interest

in and scrutiny of the developing biotechnology

industry. The role of government has likewise increased. The United States has developed a Coordinated Framework for the Regulation of Biotechnology (10); the Organization for Economic

Cooperation and Development (OECD), representing 24 nations, has developed proposals outlining

safety considerations for applications of recombinant DNA organisms in industry, agriculture,

and the environment (24); and several European

countries have developed laws or regulations

governing genetic engineering (7).

Activists opposed to environmental applications

of genetically engineered organisms have increased their visibility at the Federal, State, and

local levels. Perhaps best known is the Foundation on Economic Trends, led by Jeremy Rifkin,

which has filed several biotechnology-related legal challenges. Local groups, some in concert with

the Foundation, have become involved in debating the merits of several proposed field tests. Scientists and their constituent organizations have

also participated in the public discussion. Public

knowledge and opinion about issues concerning

science and technology in general and genetic engineering and biotechnology in particular are likely

to shape future debate.

This chapter reviews the general public’s perceptions as measured by a national survey conducted by Louis Harris and Associates for OTA,

the role of public perception in local communities where field tests have been proposed, and

the existing governmental framework for the regulation of biotechnology.

ATTITUDES AMONG THE GENERAL PUBLIC

In addition to scientific considerations, public

perceptions of the risks and benefits of biotechnology can play an important role in planned introductions of genetically engineered organisms.

As one writer has stated, “the public is a mixed

bag of people, each of whom interprets the information generated by a biotechnology company

based on a set of personal biases” (20). This, combined with the general lack of scientific knowledge with respect to these introductions and the

natural sense of unease with which the public

views high technology, serves to highlight the need

for sound information on public opinion.

Such information can provide a basis for understanding and anticipating public responses to

risk factors. It can also identify the quality and

sources of information the public draws upon,

and provide a basis for improving the communication of risk information among lay people, technical experts, and decision makers (25).

As part of a broader survey, OTA commissioned

Louis Harris & Associates to conduct a survey of

public opinion on a number of issues related to

planned introductions of genetically engineered

organisms. The survey consisted of a national sample of 1,273 adults telephoned in November 1986.

The variance for this survey is less than 3 percent for the total sample.

The results illustrate the complexities and contradictions characteristic of public attitudes in this

area. As the complete data have been published

separately (30), only a brief description of the

points most germane to deliberate release is presented here.

The American public is interested in biotechnology and genetic engineering. Two-thirds of the

public (66 percent) feel they understand the meaning of the term “genetic engineering.” In a related

question 35 percent say they have heard or read

4 5
4 6

a fair amount about the subject. However, only

19 percent has heard of any potential risks posed

by products of genetic engineering. A much higher

share (52 percent) believes it to be at least somewhat likely that these products will present some

serious danger to humans or the environment.

In spite of this, a clear majority (66 percent) thinks

genetic engineering will bring changes that will

improve their quality of life.

The American public is more positively and consistently inclined toward genetic manipulation of

plants, animals, and microbes than toward human

cell manipulation. This may in part reflect a sense

that “we have no business meddling with nature”-

a feeling strongly expressed by 26 percent of the

population (table 3-7).

Not only is there some concern about the morality of genetically manipulating organisms, there

is also concern about the potential risks that may

be posed. Between 52 and 61 percent say they

think it is at least somewhat likely that untoward

consequences (antibiotic-resistant diseases, human

birth defects, herbicide-resistant weeds, or endangered food supply) could follow. But fewer than

one in five think any of these developments are

very likely (table 3-l).

People seem willing to accept relatively high

rates of environmental risk in exchange for the

potential benefits that might be derived from deliberate release of genetically engineered organisms. A majority (55 percent) would approve an

application that would significantly increase agricultural production even if the risk of losing some

local species of plant or fish were as high as 1

Table 3-1 .—Likelihood of Specific Dangers From Use

in 1)OOO. With lower levels of risk, the degree of

public acceptance increases. But despite a general public willingness to approve the use of genetically engineered organisms in the environment

at relatively high levels of risk, a majority says

it would not approve an application if the risk were

unknown. Indeed, significantly fewer say they

would approve if the risk were “unknown but very

remote” than would approve if the risk were 1

in 1,000 (45 v. 55 percent) (table 3-2).

If there were no direct risk to humans and only

very remote risks to the environment, a majority

would approve the planned introduction of genetically engineered organisms to produce diseaseresistant crops (73 percent), oil-eating bacteria to

clean up spills (73 percent), frost-resistant crops

(70 percent), more effective pesticides (56 percent),

or larger game fish (53 percent) (table 3-3).

However, this approval is limited. Although a

large majority of the public (82 percent) approves

of small-scale experimental tests of genetically

engineered organisms for environmental applications, 53 percent feel that large-scale experimental tests should not be permitted (table 3-4).

Most Americans also say they would favor or

be indifferent to having genetically altered organisms tested in their community, assuming there

was no direct risk to humans and a very remote

potential risk to the local environment (table 3-4).

Thus, Americans seem to be pragmatic in judging genetic engineering. They are concerned about

the morality and the safety of these new developments, but are willing to greet biotechnology with

of Genetically Altered Organisms in the Environmenta

Q.: From what you have heard or read, how likely do you think it is that the use of genetically engineered organisms in the environment will (READ ITEM) —very likely, somewhat likely, somewhat unlikely, very unlikely?

Very Somewhat Somewhat Very Not

likely likely unlikely unlikely sure

Create antibiotic-resistant diseases . . . . . . . . . 180/0 43 ”/0 21“!0 7% 11 ”/0

Produce birth defects in humans . . . . . . . . . . . 18 39 24 10 9

Create herbicide resistant weeds . . . . . . . . . . . 15 41 22 11 11

Endanger the food supply . . . . . . . . . . . . . . . . . 14 38 29 13 7

Mutate into a deadly disease . . . . . . . . . . . . . . 13 33 30 14 10

Change rainfall patterns. . . . . . . . . . . . . . . . . . . 12 30 30 16 12

Increase the rate of plant or animal

extinction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 34 31 15 9

ap8rCent~Q~~ are ~~~~~”t~d as ~~l~hted ~ample estimates The unweighed base from which the sampling variance can be calculated is 1,273.

SOURCE: Office of Technology Assessment, 1987.
47

Table 3.2.-Acceptable Levels of Risk for an Environmental Application of Genetically Engineered Organismsa

Q.: Suppose that a new genetically engineered organism had been developed which would significantly increase

farm production with no direct risk to humans. Would you approve the environmental use of that organism

if the risk of losing some local species of plants or fish was (READ ITEM)?b

Not Not No

Risk level Approve approve . . sure answer

Unknown. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31%0 65% 3% 1 %

1 in 100 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 51 9 0

1 in 1000 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55 37 3 5

1 in 10,000 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65 27 3 5

1 in 100,000 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71 21 3 5

1 in 1,000,000 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74 18 2 5

Unknown, but very remote. . . . . . . . . . . . . . . . . . . . 45 46 9 5

apercentages are preS&ted as Weigtl@d sample estimates. The unweighed base from which the sampling VarianCe can be calculated is 1,273.

bApprovals are cumulative, persons who approved at a risk level were not asked to aPPrOve at lower levels of risk.

CAs a result of a programming error, those who approved at “lJnknown” risk level were not asked about specific risk levels. Those omitted Were recontacted tO complete

the risk section but we were unable to obtain res~onses from 5 Dercent of the samtYe, as a result. Althouah these are treated as “NO answer, ” most of them would

be approvals at the first risk level specified.

SOURCE: Office of Technology Assessment, 1987.

Table 3-3.—Attitudes About Environmental Uses of

Genetic Engineering Under Remote Risk Conditionsa

Q.: If there was no direct risk to humans and only very

remote risks to the environment, would you approve

or disapprove the environmental use of genetically engineered organisms designed to produce

(READ ITEM)?

Approve Disapprove Not sure

Disease-resistant

crops . . . . . . . . . . . . . . . 73% 230/o 4%

Bacteria to clean oil

spills. . . . . . . . . . . . . . . . 73 23 4

Frost resistant crops. . . . 70 27 3

More effective

pesticides . . . . . . . . . . . 56 40 4

Larger game fish . . . . . . . 53 43 4

apercentages are present~ ss weighted sample esrlrnates. The unweighed base

from which the sampling variance can be calculated is 1,273.

SOURCE: Office of Technology Assessment, 1987.

optimism if reasonable precautions are taken by

those developing, applying, and approving the new

technologies. Significant groups within the population do, however, depart from these feelings.

Nevertheless, a large majority (82 percent) believes

that research into genetic engineering should continue, and support for this research is found in

all segments of the American public (table 3-5).

This research enjoys majority support even

among those who believe human cell manipulations are morally wrong (7 I percent), that genetic

engineering products will present serious risks

(73 percent), or that it would be better if we did

not know how to alter cells genetically (63 percent) (30).

A plurality (40 percent) feels that government

funding for biological research should be increased. Only 10 percent of the public thinks that

government funding for biological research should

be cut.

Table 3.4.—Environmental Release on an

Experimental Basisa

Q.: Do you think that environmental applications of genetically altered organisms to increase agricultural productivity or clean up environmental pollutants

should be permitted on a small scale, experimental basis, or not?

Yes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82°/0

No . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .......13

Not sure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ........4

Q.: Do you think that commercial firms should be permitted to apply genetically altered organisms on

a large scale basis, if the risks of environmental

danger are judged to be very small, or not?

Yes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .42°/0

No . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. ...53

Not sure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Q.: Suppose your community was selected as the site

to test a genetically altered organism—such as bacteria that protect strawberries from frost—where

there was no direct risk to humans and a very remote potential risk to the local environment. Would

you be strongly in favor, somewhat in favor, somewhat opposed, very opposed, or really not care if

it was used in your community?

Strongly in favor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14°/0

Somewhat in favor . . . . . . . . . . . . . . . . . . . . . . . .......39

Don’t care. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .......14

Somewhat opposed . . . . . . . . . . . . . . . . . . . . . . .......21

Strongly opposed , . . . . . . . . . . . . . . . . . . . . . . . .......11

Not sure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..2

percentages are presented ss weightedsample estimates. The unweighed base

from which the sampling variance can be calculated is 1,273.

SOURCE: Office of Technology Assessment, 1987.
48

Table 3-5.—Opinions About Genetic Research

and Funding

Q.: Do you think that research into genetic engineering should be continued or should be stopped?

Continued . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82°/0

Stopped . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .......13

Not sure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ........5

Q: Do you believe that government funding for biologic

research should be increased substantially, increased somewhat, remain about the same,

decreased somewhat, or decreased substantially?

Increased substantially . . . . . . . . . . . . . . . .. ... ... ...11%

Increased somewhat . . . . . . . . . . . . . . . . . . . . . . .......29

Remain about the same . . . . . . . . . . . . . . . . . . . .......43

Decreased somewhat . . . . . . . . . . . . . . . . . . . . . . .. .....6

Decreased substantially . . . . . . . . . . . . . . . . . . . . .. .....4

Not sure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ........7

~ercentagesare presented as weighted sample estimates.The unweightedbsse

from which the sampling variance can recalculated isl,273.

SOURCE: Officeof Technology Assessment, 19S7.

Aside from supporting research, the public recognizes another important government function

associated with the development of biotechnology. A plurality (37 percent) says the government

should decide whether commercial firms should

be permitted to apply genetically engineered

organisms on a large-scale, commercial basis.

Twenty-nine percent claim this decision should

be made by an external, scientific body, while only

5 percent feel voters, taxpayers, or other community-based groups should make the decision.

Thirteen percent maintain the company involved

should make the decision, and 4 percent find a

role for industrial trade organizations (table 3-6).

Despite this relative ranking, which gives the

highest degree of approval for decisionmaking to

TabLe 3-6.—Who

governmental agencies, the public has more confidence in university scientists than in the government. when asked whose statements they

would be likely to believe about the safety of a

particular application, the majority of Americans

say university scientists (86 percent). Public health

officials score second (82 percent), environmental

groups third (71 percent), followed by governmental agencies (69 percent). In the case of conflicting statements from governmental agencies

and environmental groups, 26 percent would favor the Federal agency, 63 percent place more

trust in the environmental group, and 11 percent

are undecided or say it would depend on the specific circumstances.

In summary, the survey found that while the

public is concerned about genetic engineering in

the abstract, most people approve nearly every

specific environmental or therapeutic application

explored in this poll. The public is sufficiently concerned about potential risks to say that strict regulation is necessary, yet a majority also agree

strongly or somewhat that unjustified fears of

these new technologies have seriously impeded

the development of valuable new drugs and therapies, and that the risks have been exaggerated

(table 3-7).

As in other areas of science and technology, the

public favors the continued development and application of biotechnology because people believe

the benefits will justify the risks. Strict regulation

to avoid unnecessary risk is expected, but some

risk is clearly acceptable if sufficient benefit is expected in return.

Should Decide?

Q.: Who should be responsible for deciding whether or not commercial firms should be permitted to apply genetically altered organisms on a large scale basis--the company that developed the product, an external scientific

body, a government agency, an industrial trade association, or other group?

Party affiliation

Total Voters Republican Independent Democrat

Government agency . . . . . . . . . . . . . . . . . . . . . . . . . 37% 380/o 380/o 35% 380/o

External scientific body . . . . . . . . . . . . . . . . . . . . . . 29 31 32 34 25

Company that developed product . . . . . . . . . . . . . 13 12 12 8 16

Public/voters/taxpayers community . . . . . . . . . . . . 5 4 4 4 5

Industrial trade association. . . . . . . . . . . . . . . . . . . 4 4 3 4 4

Not sure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 5 4 5 5

All other mentions . . . . . . . . . . . . . . . . . . . . . . . . . . 8

aPerCentaQ~9 are p~esented gg Welghtti sample estimates. The Unweighed base for the total sample from which the sampling variance can be calculated iS 1,273.

SOURCE: Office of Technology Assessment, ?9S7.
49

Table 3-7.—General Perceptions Concerning Biotechnologya

Q.: I will now read you a few statements. For each, please tell me whether you agree strongly, agree somewhat,

disagree somewhat or disagree strongly. (READ EACH ITEM)

Agree Agree Disagree Disagree

strongly somewhat somewhat strongly Not sure

a. The potential danger from genetically altered cells and

microbes is so great that strict regulations are necessary . . . . 43% 34% 14% 60/0 3%0

b. The risks of genetic engineering have been greatly

exaggerated . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 40 27 10 8

c. It would be better if we did not know how to genetically alter

cells at all . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 20 34 31 2

d. The unjustified fears of genetic engineering have seriously

impeded the development of valuable new drugs and

therapies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 38 26 9 8

e. We have no business meddling with nature . . . . . . . . . . . . . . . . . 26 20 31 21 2

apercentage~ are Presented as weighted sample estimates. The unweighed sample from which the sampling variance can be calculated is 1,273

SOURCE: Office of Technology Assessment, 1987

THE ROLE OF PUBLIC PERCEPTION IN LOCAL COMMUNITIES

Companies and researchers must be prepared

to work with State and local officials and residents

when a field test of a genetically altered plant,

animal, or micro-organism is proposed. Without

local support, proposed field tests may be delayed

or canceled. To date, several proposed field tests

have met with varying degrees of State and local

support. Several States have or are currently considering legislation based on the perception that

additional State protection or coordination is

needed (see box 3-A).

The experiences of 11 communities described

in this section illustrate varying degrees of local

acceptance of proposed field tests, and varying

degrees of State and local oversight of such experiments.

Monterey and Contra Costa

Counties, California

“It was only local concern, generated in Monterey, that opened up the issue. As with events

in the nuclear industry, public opinion only becomes focused when it is in your backyard, ”

Roger Sherwood,

“The Monterey fallout continues,”

Trends in Biotechnology, July 1986.

Advanced Genetic Sciences, Inc. (AGS) of Oakland, California received the first experimental

use permit issued by the Environmental Protection Agency (EPA) for the

environmental release of a

genetically altered organism. The AGS permit was

also the first to be revoked

by EPA.

In November 1985, EPA

approved the issuance of

an experimental use permit to release strains of Pseudomonas syringae

and P. fluorescent from which the gene for the

ice-nucleation protein had been deleted. The

altered bacteria (also known as Frostban) was to

be applied to 2,400 strawberry plants on an 0.2-

acre plot surrounded by a 49-foot vegetation-free

zone in northern Salinas Valley, California.

Various individuals and nonprofit environmental organizations sought injunctive relief

against EPA’s issuance of an experimental use permit to AGS. The suit was dismissed in March 1986

on the grounds that the plaintiffs (Foundation on

Economic Trends et al.) failed to establish the likelihood of success in showing that EPA’s issuance

of a permit violated the requirements of the Federal Insecticide, Fungicide, and Rodenticide Act

(FIFRA), the National Environmental Policy Act

(NEpA) or the Administrative procedure Act (14).

In January 1986, the Monterey County Board

of Supervisors held a hearing—receiving testimony
50

BOX 3-A.—State Legislative Activity

California

In 1984) the California Legislature passed Assembly Concurrent Resolution 170 ’’to promote the biotechnology industry, while at the same time protecting public health and safety and the environment. ”

As a result, the Governor’s Task Force on Biotechnology prepared a guide to clarify the regulatory procedures for biotechnology (26).

A bill (SB 844) introduced into the Senate on March 3, 1987, would require State regulations on the

handling of biotechnologically novel organisms, making violators subject to civil and criminal penalties.

Illinois

Legislation was introduced (HB 1866) in 1987 establishing a 9-member committee to review existing

Federal regulations and monitor the release of genetically engineered organisms. The bill was passed by

the Legislature, but vetoed for budgetary reasons by Governor James Thompson on October 22, 1987.

New Jersey

New Jersey State bill S. 1123 (introduced in the 1986 session) would find that “the citizens of the state

maintain legitimate concerns about the effect that the release of genetically engineered micro-organisms

into the outdoor environment may have on the health, safety and welfare of the public, ” and establish

a 9-member commission to regulate the release of genetically engineered micro-organisms in the environment. The bill has been opposed by the Association of Biotechnology Companies (18), which is concerned

that such legislation “would put New Jersey on the map as being antagonistic to the emerging biotechnology

industry and thereby discouraging companies from locating their high-technology research and manufacturing jobs within the state” (19).

The bill was approved by the Senate but defeated by the State Assembly,

North Carolina

The North Carolina General Assembly approved the formation of a study commission approved by

the Joint Appropriations Committee, in July 1986, to determine whether a State environmental protection

agency should be formed.

Texas

HB 41, introduced during the 1987 legislative session, would have established a commission to review

the adequacy of Federal and State laws governing biotechnology, and requiring State notification of releases of genetically engineered organisms. The bill was not acted upon.

Wisconsin

Two members of the Senate Agriculture, Health and Human Services Committee recommended the

creation of a legislative council committee, that would consist of legislators and other interested parties,

to study how the State should regulate biotechnology. This followed a 1987 report from the Department

of Natural Resources that was critical of the Federal Coordinated Framework. In January 1988, a legislative

subcommittee approved a proposal that would require experimenters to apply for a State permit prior

to releasing any genetically altered organism into the environment.

SOLIRCF. Office of ‘rechnolo&\ Assessment, 1988

from EPA, California State Departments of Health jected the test bacteria into approximately 50 fruit

Services, Food and Agricuhure, AGS, scientists, trees on the rooftop of its headquarters building

the Foundation on Economic Trends, and con- without EPA approval. In March 1986, EPA suscerned members of the public. An ordinance ban- pended the AGS experimental use permit and fined

ning experiments in Monterey County for 45 days the company $20,000 on the grounds that the

was passed by the Supervisors. In February 1986, organism had been released prior to EPA approval

it was learned that AGS had 1 year previously in- and that the company had deliberately made false
51

statements on its application. The fine was later

reduced to $13)000 with an amended complaint

that AGS had not provided adequate details about

the testing method. In April 1986, the Monterey

County supervisors, relying on their zoning authority, passed legislation banning experiments

within the county for a year,

In December 1986, AGS applied to EPA and the

California Department of Food and Agriculture

for approval to conduct the field test in San Benito

County or Contra Costa County (both in California). In February 1987, the EPA reissued an experimental use permit to AGS, and the State Department of Food and Agriculture gave its preliminary

approval. In March, after receiving the approval

of the Contra Costa County Board of Supervisors,

AGS announced its intention to conduct the field

test outside of Brentwood, a town with approximately 6,000 residents. Opponents filed a legal

challenge in April, which was dismissed by a

Sacramento County Superior Court judge. On

April 24, 1987, the field test was carried out, even

though many of the plants were uprooted by vandals just hours prior to the test. A second test on

17,500 strawberry plants commenced in December 1987.

Local reaction to the AGS proposed field test

differs from the experience of other communities (described later) in several respects. The AGS

proposed field test was the first to be approved

by EPA, and the only one to be suspended by EPA.

The proposed test site in Monterey County was

also in a more populous area than the others (a

situation remedied by the relocation of the proposed release site). Finally, disclosure in the media alleging that AGS had conducted a limited environmental release on its headquarters rooftop

opened the company, and the environmental release issue generally, to closer public scrutiny.

Tulelake, California

“We object to using the Tulelake area as guinea

pigs for an experiment that won’t benefit the area

and could cause public refusal of local farm

products. ”

Joe Victrene, master, Tulelake Grange,

during public hearing, Jan. 10, 1987.

Tulelake, an agricultural town near the California/Oregon border, was the proposed test site for

the release of genetically altered P. syringae bacSiskiyou

plants. If successful,

teria on a small plot of

potatoes. Designed by

Steven Lindow and Nickolas Panopoulos, plant

pathologists at the University of California at Berkeley, the experiment involved identifying the

gene responsible for ice

nucleation, deleting the

gene, and applying the

altered bacterium to the

the treated potato plants

might resist frost damage from temperatures as

low as 23 ‘F.

The proposed environmental release of the iceminus bacteria was first approved by the National

Institutes of Health (NIH) Recombinant DNA Advisory Committee (RAC) in April 1983. In September 1983, the Foundation on Economic Trends

joined several other groups and individuals in filing suit to stop the experiment, The plaintiffs argued that NIH had violated the administrative requirements of the NEPA, which requires Federal

officials to prepare an environmental impact statement before approving an action significantly

affecting the environment. In May 1984, Judge

John Sirica issued an injunction prohibiting the

field test, and barring NIH from approving further experiments involving the release of engineered organisms until it assessed the environmental impacts of such tests, EPA began review

of the experiment in 1984. In 1986, EPA and the

U.S. Department of Agriculture (USDA) assumed

regulatory authority, pursuant to the Federal Government’s Coordinated Framework for the Regulation of Biotechnology.

Local opposition to the proposed field test received increased attention in 1986. In early May,

field test opponents circulated a petition that garnered 450 signatures. The group, “Concerned

Citizens of Tulelake,” were present at a May 1986

public meeting, and then appeared before the

Tulelake City Council and the Siskiyou and Modoc

County Board of Supervisors seeking local gov-
52

ernmental action against the experiment. On June

2, 1986, the Modoc County Board of Supervisors

passed a legally nonbinding resolution opposing

the experiment on the grounds that “the questions

and fears in the minds of the public could have

a serious and immediate adverse effect on the market for crops from the area.”

Despite the protest, on May 13, 1986, the EPA

approved the experiment and issued an experimental use permit, saying that the environmental

release posed “minimal risk to public health or

the environment.” In July, the scientists announced

that they would proceed with the experiment in

early August. On August 1, opponents of the test

(Californians for Responsible Toxic Management

and the Foundation on Economic Trends) filed suit

in Sacramento Superior Court against the University of California-Berkeley Regents and the California Department of Food and Agriculture seeking an injunction against the experiment until

environmental impact studies could be done at

State level. On August 4, 1986,2 days prior to the

proposed field test, Sacramento County Superior

Court Judge A. Richard Backus granted an 18 day

temporary restraining order. Two weeks later, the

University of California agreed to halt the experiment for 1986.

Local opposition to the Tulelake field test continued at a public hearing in January 1987, when

several residents, including the president of the

Tulelake Growers Association and the master of

Tulelake Grange, voiced opposition to the experiment, fearing crops may be boycotted by buyers.

On April 29, 1987,3 days after Advanced Genetic

Sciences, Inc. began its field test of Frostban in

Contra Costa County, the University of California

scientists planted potato tubers treated with the

ice-minus bacterium on a half-acre site at a university field station near Tulelake. On May 26, 1987,

vandals uprooted approximately half of the plants

being studied. Earth First!, an environmental

group, claimed responsibility for the raid, which

disrupted attempts to study the yields from the

plants, but not attempts to study how well the

bacteria established themselves on the plants (1.

The Tulelake scenario is similar to that of Monterey County. Both experiments involved proposed

releases of P. syringae, both followed similar regulatory approval processes, and both were linked

together in many media stories. While both experiments elicited opposition in their respective

communities, in Tulelake it focused to a significant degree on a fear that locally grown crops

would be boycotted by buyers, damaging the local economy. Although opponents of the Monterey

County and Tulelake field tests went to county

authorities to stop the experiments, opponents of

the Tulelake field test also relied on State environmental law as the basis for their suit in Sacramento County Superior Court. In both instances,

experimental plants were vandalized.

St. Charles County Missouri

“The Monsanto case is the third product to move

through regulatory agencies and is the most controversial because the bacterium produces a poison which will kill some living things, and which

may remain for some time in the soil before

dying.”

Phillip J. Hilts, Washington Post, Apr. 25, 1986.

Monsanto proposed releasing an engineered

microbial pesticide designed to protect the roots

of corn plants against black cutworm. Although

the company was prepared to proceed with the

release in mid-1984, it held

off until publication of

proposed Federal guidelines late in the year. Monsanto then became the

first company to seek EPA

approval following publication of the Federal Government’s Proposed Coordinated Framework for

Regulation of Biotechnology. In April 1986, an EPA

scientific committee recommended that the Monsanto field test should be allowed to proceed (5).

Local opposition to the Monsanto experiment

became apparent when the St. Charles City Council passed a resolution in early 1986 opposing the

procedure. This opposition ran counter to the

test’s endorsement by the 3-person St. Charles

County Commission. In March 1986, the Foundation on Economic Trends petitioned EPA to deny

Monsanto’s permit application, citing “unresolved

questions regarding the nature and magnitude of
53

the risks and benefits involved in the Monsanto

proposal.” On May 8, 1986, St. Charles County officials delivered a letter to Monsanto threatening

to sue if the company proceeded with the field

test. The letter cited county code sections prohibiting storage or processing of anything considered harmful or potentially harmful to individuals or the environment and specifying that

flood plains must be used for agricultural

purposes.

Twelve days later, EPA requested additional information in support of Monsanto’s application

for an experimental use permit. Results of the additional tests are pending.

Middleton, Wisconsin

“The Agracetus project has not elicited much

protest, however, even from the Foundation on

Economic Trends, a frequent opponent of such

tests. ‘We looked at it and it didn’t raise the kind

of fundamental questions the other tests did, ’ said

Jeremy Rifkin, the foundation’s president. Mr. Rifkin said that in general genetically modified plants

pose less risk than micro-organisms because they

can be contained more easily. ’ “

—Andrew Pollock, New York Times, May 30, 1986.

The Agracetus Corp. (a joint venture of Cetus

and W.R. Grace) proposed to insert an altered gene

for disease resistance against crown gall tumors

in 200 tobacco plant

seedlings. The genetically modified plants

were planted in a onetwentieth-acre plot in

Middleton, WI. Tobacco

was the experimental

plant of choice because

it is one of the easiest

plants to engineer ge-

/

Dane

netically. Agracetus received approval for the

field test from the NIH’s RAC, USDA, and the Wisconsin Department of Natural Resources.

On May 30, 1986, Agracetus commenced the

first authorized planting of a genetically altered

crop. The Wisconsin State Journal noted its approval for the experiment, stating that “while it

remains to be seen if the test will prove scientifically successful, it is already a winner from the

regulatory point of view .“ The editorial noted that

regulatory approval was “by the book, ” and that

the release site was situated away from roads or

people.

Unlike the proposed releases of genetically

altered organisms in Monterey County, Tulelake,

and St. Charles County, the Agracetus experiment

involved the introduction of a genetically altered

plant. Local newspaper accounts of the Agracetus experiment talked of the potential economic

gain to be realized should crops be made resistant to crown gall tumors.

Franklin County, North Carolina

“Ciba-Geigy officials have informed state and local officials of their plans. ‘I think they have done

a responsible job, ’ said Earl R. MacCormac, science advisor to Gov. James G. Martin. ‘I feel real

good about it, ’ added Ronald W. Goswick, chairman of the Franklin County Board of Commissioners.”

—Monte Basgall, Raleigh, N.C. News & Observer,

June 18, 1986.

The Agricultural Division of Ciba-Geigy Corp.,

Greensboro, NC, proposed conducting a field test

of a tobacco plant that had been genetically altered

to resist atrazine, a herFran~lin bicide used to control

weeds in corn, sorghum, and other crops.

Certain crops, including

tobacco and soybeans,

are susceptible to atrazinc. These crops can

be injured when planted in some soil types the

year after a tolerant crop treated with atrazine

was grown there, since residual atrazine persists

in the soil through the period of crop rotation.

Ciba-Geigy applied to USDA for approval of the

field test. The North Carolina Department of Agriculture asked that USDA regulate the test because

no State guidelines existed for handling such research.

USDA approved the field test in July 1986. The

North Carolina legislature subsequently approved

funding for a study commission to determine
54

whether control of State environmental responsibilities needed to be consolidated.

Mississippi and Florida

“The Rohm and Haas Company of Philadelphia,

one of the world’s largest producers of chemicals,

announced Wednesday that the U.S. Agriculture

Department had approved the world’s first field

test of genetically engineered caterpillar-resistant

plants.”

–Associated Press, Aug. 28, 1986.

Rohm and Haas developed tobacco plants altered

by the addition of a single gene from the bacterium

Bacillus thuringiensis. The

altered plants, developed

by a Belgian company for

Rohm & Haas, were designed to be resistant to

leaf-eating caterpillars.

In June 1986, Rohm and

Haas announced that it

had voluntarily applied to

USDA for permission to

field test the tobacco

plants at company-owned

research farms near Cleveland, MS and Homestead, FL. USDA issued an opinion letter in August 1986 stating that the “genetically engineered

tobacco plants are not plant pests” (51 Fed. Reg.

32237).

Prior to publicly announcing its proposed field

test, Rohm and Haas provided information to appropriate Federal, State, and local representatives

for both test sites. This

was followed up by two

h presentations for the local public and media on

~ the day the proposed

J

field tests were announced (22). Later,

presentations were

made to other interested groups, including

the Central Mississippi Chapter of the Sierra Club.

According to one member of the Sierra chapter,

the presentation elicited no grave concerns, leaving the impression that the experiment seems valid

and safe (3).

Pepin County, Wisconsin

“Does this test pose a high risk? No. EPA believes

that this field test poses little or no risk for several reasons. The genetically engineered strains

are expected to be no different than the naturally

occurring strains, except for the enhancement of

a preexisting trait (the ability to fix nitrogen from

the air to the soil). This is significant because the

naturally occurring strains have been the most

extensively studied microorganisms in agriculture

(they have been studied for nearly 100 years) and

have shown no significant adverse effects.”

—Environmental Protection Agency,

“Note to correspondents” Fact Sheet,

Apr. 29, 1987.

BioTechnica International, Inc. of Cambridge,

MA, proposed a field test of genetically engineered

strains of Rhizobium meliloti, a bacterium involved

in nitrogen fixation in alfalfa. Rhizobium is a genus of bacteria commonly

used in agriculture, with

various strains being sold

commercially to increase

the yields of legume crops.

In its proposal to EPA and

USDA, filed on February

6, 1987, BioTechnica

noted that about 80 percent of the U.S. alfalfa

acreage and 15 to 25 percent of the soybean acreage are inoculated with

nongenetically engineered rhizobia-based products. The genetically engineered Rhizobium converts atmospheric nitrogen at an increased level,

resulting in increased alfalfa yields of up to 17

percent in greenhouse studies by BioTechnica.

The BioTechnica proposal was the first application under the Toxic Substances Control Act

(TSCA) subject to the EPA biotechnology policy

published in the Federal Register on June 26,1986.

BioTechnica’s application was filed with EPA in

February 1987,

The proposed field test site is BioTechnica’s

Chippewa Agricultural Station near Arkansaw,

WI, an unincorporated town in the Waterville

Township of Pepin County. The area of the proposed test site is lightly populated and far from

urban areas. The total population of Pepin County

is approximately 7,000, of whom approximately
55

Photo credit: Kevin O’Connor

Pepin County, Wisconsin

1)000 reside in Waterville Township. The station,

located about 30 miles from Eau Claire, WI, and

75 miles from St. Paul, MN, is a 360-acre farm,

with less than 5 acres of the site designated for

the field test.

The company produced a brochure designed

to provide local residents with information regarding the proposed field test. The brochure addresses 21 questions that have been raised during the course of meetings between BioTechnica

officials and local residents (see box 3-B). Another

brochure, a nontechnical description of the field

test, was also produced.

EPA gave tentative approval for the field test

in May 1987, but delayed the experiment in order to extend the public comment period and to

review how the test would be monitored. In July

1987, a hearing sponsored by the Wisconsin Senate Agriculture, Health, and Human Services Committee was held. Although little opposition was

voiced regarding BioTechnica’s proposed test, residents did express concerns about potential future

tests (12). In August 1987, BioTechnica announced

a postponement of the field test following EPA

concerns regarding monitoring of the altered bacteria. BioTechnica concluded that the altered bacteria could not be distinguished from other common bacteria present in the soil. The company

plans to develop an alternate monitoring plan, and

expects to obtain final EPA approval in 1988 (15).

BOX 3-B. —Pepin County and Biotechnology: 21 Questions and Answers

1. What is the Chippewa Agricultural Station? The Chippewa Agricultural Station was established in January 1987 in Arkansaw (Waterville Township), Pepin County, Wisconsin. It is a wholly owned subsidiary

of BioTechnica International, Inc. of Cambridge, Massachusetts. Formed in 1981, BTI is a biotechnology

research and development company with commercial operations in agriculture and dental diagnostics. Its

stock is traded on the national over-the-counter market. The new agricultural station is BTI’s first expansion effort outside its home state and its first agricultural station. The station will be used for conventional

farming operations, as well as for agricultural research.

Z. Why did BioTechnica International choose Wisconsin? Wisconsin is the Nation’s leading dairy State,

and it is also the number one producer of alfalfa. The State has been receptive to new advances in business

and agriculture. Wisconsin has a sound policy for environmental protection which BTI supports. Field tests

of biotechnology products have already been successfully conducted within the State. The University of

Wisconsin offers outstanding research and academic expertise, and its Biotechnology Center in Madison

is a highly effective channel for communications between the academic and industrial communities and

public officials.

3. Why was Pepin County, one of the smallest counties in Wisconsin) chosen for BioTechnica International’s research station? Pepin County was selected for BTI’s first agricultural research station for

several outstanding reasons:

● Wisconsin is the nation’s top producer of alfalfa, the plant which will be field tested at the new site.

● The site is close to the University of Wisconsin’s Marshfield Research Station, where BTI is currently

conducting field tests of a new conventional silage additive. There is a possibility that this research

effort will be moved to Pepin County.
56

The area has excellent rainfall.

BTI was able to buy the 360-acre site at a very reasonable price.

An irrigation system was already in place on the farm.

The soil at the farm is a sandy loam and is uniform throughout the 360 acres, almost unheard of

benefits for an agricultural research station.

The land is exceptionally flat, minimizing runoff.

The site is 170 feet above the aquifer, making it virtually impossible for groundwater contamination

from the field tests to take place.

The site is protected by hills and trees, and is an infrequent host to severe winds and tornados.

The site lies within the 110-day corn-maturity zone and Group 2 soybean zone which make it a very

favorable crop-growing climate.

The Chippewa Agricultural Station is less than 1 mile from the home of the farm’s superintendent.

4. Will the entire research farm be used for this field test? Absolutely not. Less than 5 acres, or slightly

more than 1 percent, of the 360 acres will be used in the field test this year. Conventional crops such as

alfalfa, soybeans, corn, beans, tobacco, and rapeseed are being considered for planting in the spring and

summer of 1987.

S. Why is your company planning field tests at the farm? Both laboratory and greenhouse tests have

shown that BTI’s genetically engineered Rhizobium meliloti increases alfalfa yields by as much as 20 percent. Long before any agricultural product, conventional or genetically engineered, goes to market it must

first be field tested to determine if it is effective under the actual growing conditions encountered in the field.

6. What is Rhizobium meliloti anyway? Rhizobia are naturally occurring bacteria that exist in the soil.

The rhizobia have a symbiotic relationship with legumes such as alfalfa, soybeans, peas, and beans. Rhizobia attach themselves to the plant’s roots and establish root nodules where they live. The plant gives the

rhizobia a home and a food source; the rhizobia, in turn, convert atmospheric nitrogen into a form which

the plant can use. Rhizobium meliloti is the species that naturally associates with alfalfa.

7. How long have rhizobia been around? Farmers have been aware of this unique relationship and have

taken advantage of it in rotational farming for thousands of years. Rhizobia have been commercially available in the U.S. since the 1890s and are widely used today by farmers and home gardeners. The largest

producer today of commercial rhizobia inoculants is located in Milwaukee.

8. So what did you do to the rhizobia? Very simply, our scientists “souped up” the bacteria’s ability to

supply nitrogen to alfalfa.

9. How did they do that? Through a laborious research process that took several years, our scientists

identified the genes that are responsible for supplying nitrogen to plants. Using a surgically precise process

called gene splicing, they were able to alter certain genes so that their nitrogen-fixing, or nitrogen-gathering

ability was greatly increased.

10. Is this some kind of "Super Bug”? It definitely is an improvement of a naturally occurring bacterium,

but by no means can it be considered a dangerous “Super Bug.” Many of the strains now used commercially

have been carefully selected by the USDA for improved performance. BTI’s work is a natural outgrowth

of such efforts to provide better products to farmers.

11. How do you know it isn’t dangerous? Rhizobia are perhaps the best-studied bacteria in agriculture.

They have a specific function in nature and that is to gather nitrogen for leguminous plants. In over 90

years of commercial use, they have never been found to be dangerous to plants, animals, or man, nor

have they been known to be threats to the environment. Furthermore, BTI has tested its new strains in

the laboratory and has shown them to behave the same as their natural counterparts.

12. Couldn’t a whole field of these new organisms deplete the nitrogen supply? They couldn’t even

put a dentin it. First, the atmosphere is about 80 percent nitrogen, with over 33,000 tons of nitrogen above

every acre of land and water on earth. Naturally occurring rhizobia in an acre of alfalfa gather from 100
57

to 200 lbs. of nitrogen per year. BTI will be very pleased if its strains do twice as well. Secondly, Mother

Nature is full of checks and balances as the nitrogen cycle proves: nitrogen taken from the atmosphere

is ultimately returned to the atmosphere.

13. Won’t higher yielding plants drain more nutrients from the soil? Quite the opposite. Some of the

gathered nitrogen will leak into the soil and will be available to crops grown in rotation with legumes,

That’s why farmers apply less nitrogen fertilizer to corn planted the year after alfalfa or soybeans. Since

BTI’s strains will gather more nitrogen, it is expected that they will leave more nitrogen behind, thus further enriching the soil.

14. Can this improved version hurt cattle and eventually humans? Remember, the only alteration to

the rhizobia will be to improve their natural nitrogen-gathering ability. Based on all scientific evidenc

we have, there is nothing to indicate that there could be any adverse effects on cattle or man. The nitroge

gathering process occurs only in the roots which are not harvested. Cattle don’t eat alfalfa roots.

15. Can this new version affect other plants? No. Rhizobia function only in association with leguminous

plants. And, there are certain types of legumes for each rhizobial species. For instance, R. meliloti for alfalfa, R. japonicum for soybeans, etc. BTI’s changes to R. rneliloti will not cause it to affect any other crop

species.

16. How far can these little creatures travel on their own? Not very far at all. Their entire range of

motility is only about two-tenths of an inch per day, or, about 1 1/2 feet in a 100-day growing season.

17. Can they be blown away by the wind? They live under the soil, so it would take a pretty strong wind

to blow them away. The test site is well shielded from the wind. But the R. meliloti die without moisture

and when exposed to the ultraviolet light of the sun. So, if they were blown away, their chances of survival

would be nil.

18. Suppose a hard rain came along and some of your topsoil washed away with your new strains

and got into some streams and lakes. Could they cause a danger to fish and aquatic plants? It is highly

unlikely that the new strains could survive for any length of time in the water, since water lacks many

of the nutrients Rhizobia need to grow. They aren’t toxic, and the levels of ammonia they produce could

not possibly be high enough to have any adverse effect on aquatic plants.

l9. It sounds safe, but has it been approved by the government? Before the field testing can begin, our

application to field test must be approved by the United States Department of Agriculture and the Environmental Protection Agency. In addition, our application will have undergone very close scrutiny by Wisconsin’s Department of Agriculture, Trade and Consumer Protection, and by the Department of Natural Resources. It goes without saying that BTI welcomes and appreciates the approval of both the county leaders

and the citizens of Pepin County.

20. With so many crop surpluses being reported, why aim for yield increase? It is true that there are

many crop surpluses in the world today. With this particular field test, we are looking to achieve higher

yield increases in the 15-20 percent range. But the value to farmers comes in gains in productivity. If our

tests prove successful and we market this new product, farmers will be able to produce the same or more

alfalfa on less land at lower unit cost.

21. Once these tests have been ended, will your company pack its bags and move somewhere else?

Not very likely. We have invested a good amount of money in the farm, its rehabilitation, its new buildings,

and in its equipment. Chippewa employees are all residents of Pepin County, and all of our farm purchases

will be made through area merchants whenever possible. We have made the agricultural market a primary

objective for BTI’s growth and development as a leader in the biotechnology field. Pepin County and the

Chippewa Agricultural Station will play a major part in the long range progress and growth of BioTechnica

International, Inc.

SO[lR(:E Bm’It?rhmca Inlernat]onal, 1987
58

Bozeman, Montana

“We can sit and talk elm disease, or we can do

something about it. I choose to do something about

it .“

–Gary Strobe], Aug. 13, 1987.

Gary Strobel, a professor of plant pathology at

Montana State University, injected 14 trees with

a fungus that causes Dutch elm disease. Half of

the trees had previously been injected with genetically altered bacteria designed to fight the disease.

The experiment, carried

out without Federal Government approval and

without the knowledge of

the university’s biosafety

committee, was initiated in

June 1987. Two months later, the uninfected trees

were dead; the injected trees were still alive. Overshadowing the scientific data, however, was the

publicity aroused by Strobel’s experiment as portrayed in headlines such as “Genetic Engineering

Rules: The Making of a Monster” (34).

The 14 trees were located on the Montana State

campus. Strobel initiated the field test in June in

order to obtain results during the current year’s

growing season. When EPA contacted him in July

1987 requesting further information on the test,

Strobel notified the agency that the experiment

had already begun. In August 1987, Strobel notified his university’s biosafety committee of the

details of the field test. Shortly thereafter, the biosafety committee recommended that the trees be

uprooted and burned. EPA and the university

president reprimanded Strobel, and Strobel himself cut down the trees and terminated the experiment in early September.

obedience, ” a characterization he withdrew 2

weeks later. The EPA sent Strobel a notice of warning, telling Strobel that for a period of 1 year, any

application for a proposed test would have to be

“cosponsored by the university, a colleague or

some other responsible party” (33). A written

warning was the most stringent legal option available to EPA under FIFRA penalty provisions (7

U.S.C. 136(a)(2)). A Montana State University administrative review panel recommended that the

university’s administration issue a formal reprimand. In January 1988, NIH decided that Strobel

violated no NIH Guidelines in his experiments.

The Montana State experience differed from the

others in that the researcher had not obtained

permission from either the Federal Government

or the university prior to carrying out the experiment. At first, Strobel called his action “civil dis-
59

Unhappiness with the Federal regulatory framework was voiced by Strobel, and by Montana State

University President William Teitz, who in reprimanding Strobel also complained of the “tangled

interpretations, definitions, procedures, exceptions, inclusions, and classifications that dominate

today’s biotechnical research. ”

Argentina

“There is a lesson to be drawn from this which

I wish to pass on to my scientific colleagues: extreme caution is to be observed in conducting cooperative programs with organizations and scientists who have political motives which intrude

upon even the most straightforward attempts to

conduct scientific research for the benefit of huinanity. ”

—Hilary Koprowski, Director, Wistar Institute

The Wistar Institute of Philadelphia produced

a genetically engineered rabies vaccine, which it

provided to the Pan American Health Organization (PAHO) for field testing in Argentina. In July

1986, 20 cattle were inoculated at a PAHO agriArgentina

culture station in Azul,

Argentina (approximately 180 miles south

of Buenos Aires). In September 1986, the Argentine government

learned of the field test

through a letter written

by an Argentine trainee. The government

barred further tests,

claiming that the vaccine posed a health

threat. On November

11, 1986, the New York

Times reported that

Wistar conducted tests the previous summer without obtaining approval from either the Argentine

or United States governments. In December 1986,

NIH sought written assurance from Wistar that

no Federal funds were used to test the rabies vaccine in Argentina. Wistar replied that although

the rabies vaccine research program received Federal funding, $100,000 for the Argentina field test

came from private sources. In January 1987, NIH

announced that the experiment did not violate NIH

guidelines.

Criticism of the Wistar-PAHO experiment was

voiced editorially by the New York Times (29) and

Los Angeles Times (6) as well as by 134 Argentine

scientists, who alleged violations of ethical, ecological, and safety rules (16). The director of the

Wistar Institute maintained that media accounts

ignored the results of the experiment and that

the vaccine was both efficient and safe; that Wistar

merely provided the vaccine to PAHO, anticipating that the health organization would obtain any

necessary governmental approvals in Argentina;

and that representatives of an Argentine scientific organization approached Wistar in 1984 proposing to conduct the same trial undertaken by

PAHO.

New Zealand

Another overseas test of a genetically engineered

vaccine (Bacteroides nodosus) involved researchA Los Angeles Times

what they intended to

do” (6). In November 1986, the Foundation on Economic Trends announced it would ask USDA and

other Federal agencies to investigate the New

Zealand experiment and determine whether any

United States laws were broken.
60

Great Britain

“A cabbage patch somewhere in Britain is the

unlikely venue for a world first. Since last month,

the patch has been home for a collection of caterpillars that have been infected with a unique virus

which does not occur naturally. The experiment

may help virologist to engineer safe, artificial

viruses that kill pests before they can destroy

crops. ”

—Steve Conner, New Scientist,

Oct. 16, 1986.

Researchers at the Institute of Virology in Oxford conducted the world’s first release of a genetically engineered virus when infected caterpillars were released in September 1986. The virus

was engineered to contain a genetic marker so it

could be tracked. The goal of the experiment was

to evaluate survival and dispersal of the virus in

the environment. If the experiment is successful,

the researchers plan to introduce other properties into the organism, with along-term goal of developing custom-designed

viral insecticides (2).

The Oxford researchers

consulted with the United

Kingdom Advisory Committee on Genetic Manipulation; the Nature Conservancy Council; the

Ministry of Agriculture,

Fisheries and Food; and

the Department of the

Environment prior to the

environmental release. In

the European Parliament,

news of the U.K. experiment was met with disapproval by representatives of the Green Party,

who have opposed environmental release of genetically altered organisms.

THE EXISTING REGULATORY FRAMEWORK

The development of recombinant DNA techniques during the 1970s raised concerns about

potential hazards posed by the new technologies.

Recognizing a need to establish consensus, scientists became involved in discussing recombinant

DNA technology and its potential risks. The International Conference on Recombinant DNA

Molecules (better known as the Asilomar Conference) convened 140 scientists in February 1975

to address self-regulation of research involving

recombinant DNA technology until its safety could

be assured. Recommendations were issued assigning risk categories to various recombinant DNA

experiments and containment levels for each (28).

Federal regulation of genetically altered organisms began in 1976, when NIH adopted “Guidelines for Research Involving Recombinant DNA

Molecules.” These stringent guidelines established

containment standards and review procedures to

be applied by Institutional Biosafety Committees

at each institution receiving Federal support for

research (31). The guidelines were modified and

relaxed several times as more became known

about the safety of various organisms and technologies.

The NIH Recombinant DNA Advisory Committee was the primary Federal entity for reviewing

and monitoring recombinant DNA research until

1984, when its oversight of field tests was challenged by a lawsuit alleging that NIH had violated

provisions of the National Environmental Policy

Act (13). This act requires all Federal agencies to

prepare an analysis prior to any action that may

significantly alter the environment.

In 1984, the White House Office of Science and

Technology Policy (OSTP) published a Proposed

Coordinated Framework for the Regulation of Biotechnology (11) in order to ensure the safety of

biotechnology research and products. This document proposed policies for Federal agencies responsible for reviewing the research and products of biotechnology. It also proposed the

establishment of a new, centralized advisory committee within the Department of Health and Human Services (DHHS) to coordinate responses to

scientific questions raised by applications received

by the various Federal agencies.

Following a period for public comment, OSTP

decided against establishing a committee within

L

.
61

DHHS. Instead, a Biotechnology Science Coordinating Committee (BSCC) was formed “to monitor the changing scene of biotechnology and serve

as a means of identifying potential gaps in regulation in a timely fashion, making appropriate recommendations for either administrative or legislative action.” (50 Fed. Reg. 47174). In the same

notice, OSTP published an index of laws conferring authority that could be used to ensure the

safety of biotechnology-related products. Many

elements of the Proposed Coordinated Framework

were incorporated into the Coordinated Framework published by OSTP on June 26, 1986 (51

Fed. Reg. 23301).

Coordinated Framework for

Regulation of Biotechnology

The Coordinated Framework includes separate

descriptions of the regulatory policies of the

FDA, EPA, Occupational Safety and Health Administration (OSHA), and USDA; and the research

policies of NIH, the National Science Foundation

(NSF), EPA, and USDA.

The Coordinated Framework mandates both the

agencies responsible for approving commercial

biotechnology products (table 3-8) and the jurisdiction for biotechnology research proposals (table

3-9). Where jurisdiction overlaps, a lead agency is

designated. The goal is to operate in an integrated

and coordinated fashion to cover the full range

of plants, animals and micro-organisms derived

by the new genetic engineering techniques.

FDA proposed no new procedures for regulating biotechnology products, instead relying on existing authority for approving drugs, human biologics, animal food additives and drugs, and

medical devices. The FDA review relies on “scientific evaluation of products, and not . . . a priori assumptions about certain processes” and “is

conducted in light of the intended use of the product on a case-by-case basis” (51 Fed. Reg. at 23309).

EPA addressed regulation of microbial products

subject to two Federal statutes: the Federal Insecticide, Fungicide, and Rodenticide Act and the

Toxic Substances Control Act. EPA’s review under FIFRA places “particular emphasis on smallscale field testing of genetically engineered, nonindigenous, and pathogenic microbial pesticides” (5 I

Table 3-8.—Agencies Responsible for Approval of

Commercial Biotechnology Products

Biotechnology products Responsible agencies

Foods/food additives . . . . . . . . . . . . FDA*, FSISa

Human drugs, medical devices,

and biologics . . . . . . . . . . . . . . . FDA

Animal drugs . . . . . . . . . . . . . . . . . . . FDA

Animal biologics. . . . . . . . . . . . . . . . APHIS

Other contained uses . . . . . . . . . . . EPA

Plants and animals. . . . . . . . . . . . . . APHIS, b FSIS, = F D A

C

Pesticide micro-organisms

released in the environment

All. . . . . . . . . . . . . . . . . . . . . . . . . EPA, d APHISb

Other uses (micro-organisms):

Intergenetic combination . . . . . . EPA,d APHISb

Intrageneric combination:

Pathogenic source organism

1. Agricultural use . . . . . . . . . . . . APHIS

2. Non-agricultural use. . . . . . . . . EPA,d APHISb

No pathogenic source

organisms. . . . . . . . . . . . . . . . . . EPA Report

Nonengineered pathogens:

1. Agricultural use . . . . . . . . . . APHIS

2. Non-agricultural use. . . . . . . EPA,d APHISb

Nonengineered nonpathogens . . . . EPA Report

“Designates lead agency where jurisdictions may overlap; FDA, Food and Drug

Administration.

aF!jlS, Food Safety and Inspection Service, under the Assistant Secretary of

Agricultural for Marketing and Inspection Services is responsible for food use

bAPHIS, Animal and Plant Health Inspection Service, is involved when the microorganism is plant pest, animal pathogen, or regulated article requiring a permit

CFDA is involved when in relation to a food use.

dEpA requirement will Only apply to environmental release under a “Significant

new use rule” that EPA intends to propose.

SOURCE: 51 Fed. Reg. 23339.

Fed. Reg. 23313), while TSCA provides EPA authority to regulate any organic or inorganic substance

of a particular molecular identity, including any

combination of such substances occurring in

whole or in part as a result of a chemical reaction

or occurring in nature. Under FIFRA, all field tests

of genetically altered organisms require an experimental use permit. TSCA requires a manufacturer

to adhere to premanufacturing notice requirements (see box 3-C).

USDA stated that ‘(agriculture and forestry

products developed by biotechnology will not differ fundamentally from conventional products

and the existing regulatory framework is adequate

to regulate biotechnology” (51 Fed. Reg. at 23336).

The USDA policy statement listed nine statutes

considered most relevant to biotechnology applications (table 3-10).

Of primary interest is USDA’s regulation of

“plant pests’’-any living stage of any insects, mites,

nematodes, slugs, snails, protozoa, or other inver-
~.-z

Table 3-9.—Jurisdiction for Biotechnology

Research Proposals

Proposed research Responsible agencies

Contained research, no release in

environment:

1. Federally funded. . . . . . . . . . . .

2. Non-federally funded . . . . . . . .

Foods/food additives, human

drugs, medical devices

biologics, animal drugs:

1. Federally funded. . . . . . . . . . . .

2. Non-federally funded . . . . . . . .

Plants, animals and animal

biologics:

1. Federally funded. . . . . . . . . . . .

2. Non-federally funded . . . . . . . .

Pesticide micro-organisms:

Genetically engineered:

Intergeneric . . . . . . . . . . . . . . . .

Pathogenic intrageneric . . . . . . .

Intrageneric nonpathogen . . . . . . . .

Nonengineered:

Nonindigenous pathogens . . . . .

Indigenous pathogens . . . . . . . . .

Nonindigenous nonpathogen . . .

Other uses (micro-organisms)

released in the environment:

Genetically engineered:

Intergeneric organisms:

1. Federally funded. . . . . . . . . .

2. Commercially funded. . . . . .

Intrageneric organisms:

Pathogenic source organism:

1. Federally funded. . . . . . . . . . . .

2. Commercially funding . . . . . . .

Intrageneric combination:

No pathogenic source

organisms . . . . . . . . . . . . . . . . .

Funding agencya

NIH or S&E voluntary

review, APHISb

FDA, C NIH guidelines

and review

FDA, C NIH voluntary

review

Funding agency,a

! APHIS

APHIS, b S&E

voluntary review

EPA, d APHIS, b S&E

voluntary review

EPA, d APHIS, b S&E

voluntary review

EPA, d S&E voluntary

review

EPA, d APHIS

EPA, d APHIS

EPA

Funding agency,a

APHIS, b EPAd

EPA, APHIS, S&E

voluntary review

Funding agency,a

APHIS, b EPAd

APHIS, b E PA

d (if nonagricultural use)

EPA repor t

Nonengineered . . . . . . . . . . . . . . . . . EPA report, * APHISD

“Designates lead agency where jurisdictions may overlap.

aReview and approv~ of research protocols conducted by NIH, S&E, or NSF.

bEPA jurisdiction for research on a plot greater than 10 acres.

CApHIS issues permits for the importation and domestic shipment of certain

plants and animals, plant pests and animal pathogens, and for the shipment

or release in the environment of regulated articles.

dEpA reviews federally funded environmental research only when it is for

commercial purposes.

KEY: APHIS: Animal and Plant Health Inspection Service; EPA: Environmental

Protection Agency; NIH: National Institutes of Health; S&E: United States

Department of Agriculture Science and Education.

SOURCE: 51 Fed. Reg. 23305.

tebrate animals, bacteria, fungi, or parasitic plants

or reproductive parts thereof, viruses, or any

organisms similar to or allied with any of the forgoing, or any infectious substances, which can

directly or indirectly injure or cause disease or

damage in any plants or parts thereof, or any processed, manufactured, or other products of plants”

(7 U.S.C. 150aa(c)).

USDA subsequently issued a final rule on the

“introduction of organisms and products altered

or produced through genetic engineering which

are plant pests or which there is reason to believe are plant pests” (52 Fed. Reg. 22891). The

rule sets forth procedures for obtaining a permit

prior to the introduction of organisms and products that present actual or potential plant pest

risks. The final rule also mandates State notification and review of permits in addition to Federal

review.

Because many applications of genetically engineered organisms in the environment will be agricultural, USDA is placed in a dual role of regulating the technology while attempting to fulfill its

statutory mandate “to procure, propagate, and distribute among the people new and valuable seeds

and plants” (7 U.S.C. 2201). In addition, instances

are likely to arise where microorganisms that are

not intended for agricultural purposes could still

represent a plant pest. The Coordinated Framework addresses this issue, laying out USDA and

EPA jurisdictional agreements whereby both agencies will “perform independent reviews, focusing

on independent objectives” (51 Fed. Reg. 233.59).

EPA will review pursuant to TSCA or FIFRA, while

USDA will review pursuant to the plant pest

statute.

Table 3-10.–Statutes Applicable to

USDA-Regulated Biotechnology

Virus-Serum Toxic Act (21 U.S.C. 151-158)

Federal Plant Pest Act (7 U.S.C. 150aa-150jj)

Plant Quarantine Act (7 U.S.C. 151-164, 166, 167)

Organic Act (7 U.S.C. 147a)

Federal Noxious Weed Act (7 U.S.C. 2801 et seq.)

Federal Seed Act (7 U.S.C. 551 et seq.)

Plant Variety Protection Act (7 U.S.C. 2321 et seq.)

Federal Meat Inspection Act (21 U.S.C. 601 et seq.)

Poultry Products Information Act (21 U.S.C. 451 et seq.)

SOURCE: 51 Fed. Reg. 23339.
63

Box 3-C.— EPA’s Statutory Mandate: FIFRA and TSCA

Under the Coordinated Framework for Regulation of Biotechnology, the Environmental Protection Agency

is addressing certain microbial products under two statutes: the Federal Insecticide, Fungicide, and Rodenticide Act; and the Toxic Substances Control Act.

Federal Insecticide, Fungicide, and Rodenticide Act

The Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) was enacted in 1972 (PL 92-516), bringing under one statute various Federal initiatives that had been in effect as far back as 1910. FIFRA regulates

the use and safety of approximately 1 billion pounds of pesticide products produced and sold annually

in the United States. Approximately 70 percent of the $6 billion worth of such products are herbicides

and agricultural chemicals (4).

FIFRA mandates the registration of pest control products and defined “economic poisons” with the

EPA prior to the production or sale of such product. In order to register a product, an applicant must

submit complete data on the product as provided in the statute (7 USC 136a). Any person may apply for

an experimental use permit for a pesticide. Such a permit can be issued only if it is determined “that the

applicant needs such permit in order to accumulate information necessary to register a pesticide. . .“(7

USC 136c)

Civil penalties for violations of FIFRA vary, depending on whether or not the violator is considered

to be a private applicator. A private applicator must receive a written warning for a first offense. Subsequent violations can result in a fine of $1,000 for each violation. Other registrants can be assessed $5,000

for each offense, including the first offense.

Toxic Substances Control Act

The Toxic Substances Control Act (TSCA) (PL 94-469) was enacted by Congress in 1976. In contrast

to other environmental statutes specifically regulating the quality of water, air, or natural resources, TSCA

gave EPA broad authority to regulate “chemical substances and mixtures.” Such substances and mixtures

include “any organic or inorganic substance of a particular molecular identity, including any combination

of such substances occurring in whole or in part as a result of a chemical reaction, or occurring in nature,

and any element or uncombined element; statutory exceptions to this definition include pesticides (as defined in FIFRA, above), tobacco, special nuclear material, food, food additive, or drug. TSCA, therefore,

is not designed only to regulate toxics, but also the large number of chemical substances and mixtures

to which human beings and the environment are exposed each year.

Under TSCA, the manufacturer of a new chemical must submit to EPA a premanufacture notice (PMN)

that describes test data relating to the identity, use, amount, chemical identity, disposal, etc. EPA then has

90 days to consider the notice and decide whether to approve production. TSCA allows EPA to ask for

additional data, and to limit or ban production.

TSCA’s civil penalties are harsher than those under FIFRA: up to $25,000 for each violation, with each

day a violation continues constituting a separate violation.

BioTechnica’s proposed field test in Pepin County, Wisconsin (see page 54) represents the first time

TSCA has been used to regulate the release of a genetically engineered organism in the environment. Proponents of EPA use of TSCA contend that the statute is well-suited for evaluating the risks of field tests on

a case-by-case basis. Critics contend that the 90 day review period is too short to determine the risks of

a particular experiment, and that the decision-making process within EPA could prevent meaningful, accountable, pre-release screening (17).
64

OSHA stated that its authority under the Occupational Safety and Health Act of 1970 (29 U.S.C.

et seq.) is sufficient to protect employees in the

field of biotechnology, and that no further regulation is necessary.

Challenges Facing Regulators

The Coordinated Framework noted “that future

scientific developments will lead to further refinements” of the regulations (51 Fed. Reg. at 23303).

Several challenges face regulators as they work

with the new Framework:

● Definitions: The Coordinated Framework

provided definitions for “intergeneric organism” (i.e. anew organism) and for “pathogen.”

The OSTP notice makes clear that “[t]hese definitions are critical . . . for the regulation of

biotechnology because they establish the

types of the organisms subject to certain kinds

of review” (51 Fed. Reg. 23302). NSF, FDA,

and USDA announced that certain definitions

“may be ambiguous” (51 Fed. Reg 44397). In

addition, the BSCC “is attempting to define

what constitutes ‘release into the environment’.” Release into the environment, “for the

time being, will have somewhat varying definitions for the regulatory and research review of the different agencies” (51 Fed. Reg.

23307). In October 1986, an NIH Committee

reviewing allegations surrounding an alleged

field test of a pseudorabies vaccine noted that

“we found ambiguities in the NIH Guidelines,

both in regard to whether the pseudorabies

vaccine used in the field test consisted of ‘recombinant DNA molecules,’ and whether the

field test constituted ‘deliberate release into

the environment’” (32).

● Risk Assessment and Management: The

continuing need to protect the environment

and public health requires a balancing of the

known risks of existing technologies and the

potential risks of new technologies against the

benefits derived from these technologies. Because the risks involved inmost proposed releases of genetically engineered organisms

into the environment cannot be measured

precisely, there will be some uncertainty in

determiningg the safety of proposed fieldtests.

● The Need To Promote a Favorable Eco-

●

●

●

nomic Climate for Research and Product

Development. Excessive regulation will

make it difficult for biotechnology-related research projects to move from the controlled

environment of the laboratory to the field.

Initially strict regulation of recombinant DNA

research, through NIH guidelines, was revised

and relaxed as increased scientific knowledge

revealed the safety of various applications.

Decreased regulation of genetically engineered organisms in the environment may

also be possible if warranted by scientific developments. If proposed field tests are severely restricted, curtailed, or delayed, researchers may conduct research and product

development in other countries that are more

hospitable to such technology.

Assurance That Regulation of One Type of

product Does Not Hinder Development of

other products: The new Framework provides several Federal agencies with jurisdiction over a wide range of research and products (e.g., food, drugs, pesticides, vaccines,

and medical technologies). Some agencies may

regulate this new technology better than

others. Mistakes made in regulating research

or products could erode public confidence

in the entire Coordinated Framework, which

could in turn lead to inconsistent regulatory

review of proposed planned introductions of

genetically engineered organisms.

Jurisdiction of Federal Agencies Regulating Biotechnology Agencies need to adjust

to the integrated Framework, which establishes a lead agency for those instances where

regulatory oversight or review is to be performed by more than one agency (see tables

3-8 and 3-9). Environmental concerns, for example, fall under the direct mandate of EPA.

All Federal agencies, however, must prepare

an environmental analysis for major actions

significantly affecting the quality of the human environment.

The Legality Applicability and Scope of

Current Statutes To Regulate the Release

of Genetically Engineered Organisms: The

Coordinated Framework is predicated on the

use of existing statutes (e.g., TSCA and FIFRA)

to handle emerging issues in the regulation

of biotechnology. The applicability (e.g., use
65

of a conventional chemical statute to regulate genetically engineered organisms) of such

statutes may be challenged in court, as may

the scope and legality of other statutes. In

addition, each statute relied upon presents

administrative law issues that could result in

court cases.

Promotion v. Regulation: Two Federal

agencies–NIH and USDA—are charged with

regulating biotechnology research and development while at the same time having statutory mandates to promote research and product development. NIH promotes and funds

much of the nation’s biomedical research pursuant to the Public Health Act, while at the

same time regulating that research, including biotechnology research. USDA is mandated to procure, propagate, and distribute

new and valuable seeds and plants; at the

same time, it must regulate and potentially

curtail new products through the application

of several statutes designed to eradicate potential problems (e.g., plant pests).

Consistent Penalties for Violators: Because

existing statutes are being used to regulate

biotechnology, varying penalties can result.

For example, the two statutes relied upon by

EPA (TSCA and FIFRA) carry different penalties. As a result, penalties could merely reflect the statute employed, not the actual

severity of the civil or criminal act.

The Role of State and Local Governments

in Regulating Biotechnology and Environmental Release of Genetically Engineered

Organisms: State environmental, authority

and county zoning and land use ordinances

have played an important role in several proposed field tests and could play an increasing role in future tests. Several States are considering regulations governing the release of

genetically engineered organisms in the environment. Where Federal and State Governments claim subject matter authority over

such releases, the issue of Federal preemption of State action could arise.

Public perceptions: The environmental applications of genetically engineered organisms

will be affected considerably by public opinion, particularly in communities that host the

early field tests. Ultimately, any applications

approved for general use will feel the weight

of public opinion. Regardless of the scientific

judgments by experts who will develop and

consider these applications, a hostile public

or one unconvinced of the value of these developments will give the biotechnology industry a difficult time in the marketplace. Several proposed field tests have already been

the targets of protest in some communities,

although other proposed field tests have met

with little or no local opposition.

European and Japanese Regulation

In addition to action in the United States, several European nations have begun to assess the

need for regulatory review of genetically engineered organisms in the environment. Both the

European Economic Community (EEC) and several member nations have considered regulatory

issues over the last few years.

The EEC established a biotechnology steering

committee in February 1984 to coordinate biotechnology policies. In 1986, a meeting was held

by member-state officials to discuss the regulation of releases of genetically engineered organisms in the environment (35). In November 1986,

a commission report highlighted the need for collective action, and announced that proposals

would be developed for Community action on “a)

levels of physical and biological containment, accident control, and waste management in industrial applications, and, b) authorization of planned

release of genetically engineered organisms in the

environment” (8). This initiative occurred as several member states were taking steps to regulate

biotechnology:

●

●

Denmark enacted legislation in 1986 preventing the deliberate release of any organism that is the product of recombinant DNA

technology as well as any organism resulting

from gene deletion or cell hybridization (23).

The Danish law forbids such experiments unless approval is obtained from the environment minister.

France in 1987, established a 15-member

panel of scientists, under the jurisdiction of

the Ministry of Agriculture, to review proposed deliberate release experiments on a
66

case-by-case basis and to consider the need

for future regulation. Notification of any intent to use recombinant DNA technology must

be made to the Ministry of Research and

Higher Education (23). Field tests involving

the nitrogen-fixing bacteria Rhizobium began

in March 1987.

The Netherlands established an advisory

committee on recombinant DNA activities to

regulate such research.

The United Kingdom developed voluntary

guidelines published in April 1986 that encourage any person planning a deliberate release of an engineered organism to contact

the Health and Safety Executive (9). Proposed

regulations would require scientists to notify

the Executive of any general intention to conduct experiments involving genetic manipulation as well as individual notification forcertain high risk experiments (27).

Sweden established a special commission in

1984 to study whether tighter regulations

were needed for recombinant DNA research.

The advisory committee recommended that

existing occupational health and environSUMMARY AND

recent poll indicates that a large majority of

Americans (82 percent) approve of small-scale experimental tests of genetically engineered organisms for environmental applications. Most people

approve of such applications for a variety of purposes, and a majority appear willing to accept relatively high levels of risk to the environment in

exchange for the potential benefits that might be

derived from environmental applications of genetically engineered organisms.

The experiences of local communities illustrate

the varying degrees of local support for fieldtests

of genetically altered plants, animals, and microorganisms. In several instances, local opposition

thwarted or delayed proposed field tests. In other

communities opposition was minimal. Opponents

of proposed field tests have relied on State environmental laws, local laws (e.g., zoning laws,

county ordinances), political pressure (e.g., petition drives, public meetings), and even physical

sabotage of test sites to achieve their objectives.

mental protection oversight is adequate, and

that stricter regulations are not needed.

The Federal Republic of Germany classifies

experiments in four categories; releases of

organisms into the environment fall into the

prohibited category, although researchers

may apply for an exception. A parliamentary

commission was formed in 1984 to study the

potential scientific, social, and legal implications of gene technology. The report recommended a 5-year moratorium on environmental releases of genetically altered viruses

(except for those used as vaccines in human

and veterinary medicine) and of micro-organisms into which genetically foreign genes

have been inserted (8).

Japan regulates biotechnology through several ministries. Pharmaceutical production

has developed under guidelines developed by

the Ministry of Health and Welfare. Regulation of agricultural biotechnology is expected

to become more important as the number of

permits for research and production increase

(21).

CONCLUSIONS

Where opposition has been minimal, companies

and individual researchers have generally informed governmental and citizens’ groups about

their scientific goals and objectives, the degree

of regulatory review of the experiment, safety considerations, and the economic impact of such experiments on the local economy.

Factors specific to individual cases may affect

the degree of public support or opposition to a

proposed field test. Genetically altered microorganisms, for example, have elicited more public concern than proposed field tests of plants. The

extent of local support or opposition may also depend on the degree to which a proposed field test

is perceived as a first (e.g., the first release of a

microorganism, first application under TSCA, first

release in a particular State).

The development of recombinant DNA techniques during the 1970s led to self-regulation by

scientists and, later, regulation by the Federal Gov-
67

ernment, The Coordinated Framework for Regulation of Biotechnology, published by the White

House Office of Science and Technology in 1986,

describes a comprehensive Federal regulatory policy to ensure the safety of biotechnology research

and products. Several challenges face regulators

as they adjust to the new Framework: defining

key terms; balancing risks and benefits of the new

technology; maintaining a favorable economic climate for research and product development; assuring that regulation of one type of product does

not hinder development of other products; determining jurisdiction when regulatory oversight

or review is to be performed by more than one

Federal agency; balancing technology promotion

and regulation; establishing consistent penalties

for violators; resolving potential challenges to the

legality, applicability, and scope of current statutes; balancing technology promotion and regulation; establishing consistent penalties for violatons; resolving potential jurisdictional conflicts between Federal, State, and local governments; and

assessing public opinion.

CHAPTER 3 REFERENCES

1. Anderson, I., New Scientist 14(1563):32, 1987.

2. Bishop, D., “UK Release of Genetically Marked Virus, ” ATature 323(6088):496, 1986.

3. Buhner, B., Program Coordinator, Sierra Club, Central Mississippi Chapter, Jackson, MS, personal communication, May 6, 1987.

4. Bureau of National Affairs, U.S. Environmental

Laws (YVashington, DC: Bureau of National Affairs,

1986).

5. Carpenter, W. D., Vice President, Technology, Monsanto Agricultural Co., St. Louis, MO, personal communication, June 10, 1987.

6. “Cheating at the Outer Edge, ” Los Angeles Times,

Nov. 14, 1986.

7. Commission of the European Communities, Communication from the Commission to the Council:

A Community Framework for the Regulation of Biotechnology (Brussels, Nov. 4, 1987).

8. Committee of Inquiry of the loth Bundestag on the

Opportunities and Risks of Gene Technology, Gene

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9. Conzelman, C., and Claveloux D., “Europe Fails To

Agree on Biotech Rules)” New Scientist 111(1516):

19-20, 1986.

10. Executive Office of the President, Office of Science

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11, Executive Office of the President, Office of Science

and Technology Policy, “Proposed Coordinated

Framework for the Regulation of Biotechnology, ”

Federal Register 49:50856, 1984.

12. Forster, H., Clerk of the Wisconsin Senate Agriculture, Health, and Human Services Committee, personal communication, July 30, 1987.

13. Foundation on Economic Trends v. Heckler, 587

F.Supp 753 (D.C. 1984), 756 F.2d 143 (D.C. Cir 1985).

14. Foundation on Economic Trends, et al. v. Thomas,

et al., 637 F. Supp.25 (D.D.C. 1986).

15. Glass, D.J., Director, Patents and Regulatory Affairs,

BioTechnica International, Inc., Cambridge, MA,

persona] communication, Sept. 16, 1987.

16. Grigera, P. R., et. al, “Wistar’s Export to Argentina, ”

Nature 324(6098 ]:610, 1986.

17. Harlow, R. E., “The EPA and Biotechnology Regulation: Coping with Regulatory Uncertainty,” The Yale

Law Journal 95:533, 1986.

18. Hyer, W .C., Managing Director, Association of Biotechnology Companies, Washington, DC, personal

communication, Mar. 24, 1987.

19. Hyer, W.C., “On Managing Biotechnology,” iVew

York Times, Sept. 28, 1986.

20. Iles, A., “Public Understanding as a Key to Commercial Success, ” Biotechnology 5(8):856, 1987.

21. McCormick, D., “Japan: Co-ordinated Action,”

Biotechnology 5(12):1279, December 1987.

22. Meeusen, R. L., Manager, Agricultural Biotechnology, Rohm & Haas Co., Springhouse, PA, personal

communication, Apr. 23, 1987.

23. Newmark, P., “Discord and Harmony in Europe, ”

Bio/Technology 5(12):1281, December 1987.

24. Organization for Economic Cooperation and Development, “Recommendations of OECD’S Council

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of Recombinant DNA Organisms in Industry, Agriculture, and the Environment (Paris, 1986).

25. Slovic, P., “Perception of Risk,” Science 236:280-

285, 1987.

26. State of California, Interagency Task Force on Biotechnology, BiotechnoZo~ Permits and Regulations

(Sacramento, CA, 1986).

27. Stewart, A., “U.K. Revises Rules on Gene Engineering,” The Scientist 1(26):7, Nov. 30, 1987.

28. Tangley, L., “New Biology in a New Era, ” Bioscience

35(5):270, 1985.

29. “Toying With Genes, and Argentina, ” New York
68

30.

31.

32.

Times, Nov. 12, 1986.

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New Developments in Biotechnology, 2: Public Perceptions of Biotechnology-A Background Paper,

OTA-BP-BA-45 (Washington, DC: U.S. Government

Printing Office, May 1987).

U.S. Department of Health and Human Services,

National Institutes of Health, Guidelines for Research Involving Recombinant DNA Molecules, May

1986.

U.S. Department of Health and Human Services,

National Institutes of Health, “Report of Committee Established to Review Allegations of Violations

of National Institutes of Health Guidelines for Research Involving Recombinant DNA Molecules (NIH

Guidelines) in the Conduct of Field Tests of a Pseu -

dorabies Vaccine at Baylor College of Medicine

and/or Texas A&M University,” Oct. 9, 1986.

33. U.S. Environmental Protection Agency, Office of

Public Affairs, Environmental News, “EPA Restricts

Further Genetic Experimentation by Montana

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34. U.S. News & world Report, Aug. 31, 1987, p. 10.

35. Whitehead, C., “Controlling the Risk to Health and

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European Community Doing?” Trends in Biotechnology 5(40):123, 1987.
Chapter 4

Genetic Considerations

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CONTENTS

What is Known About Horizontal Transfer of Genes? . . . . . . . . . . . . . . . . . . . . . .

What Genetic Considerations Should Be Evaluated in Planned Introductions?. . .

Predicting the Potential Impacts of Horizontal Transfer . . . .

Intrinsic Factors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . + . . . . . .

Extrinsic Factors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Technologies To Monitor Horizontal Gene Transfer . . . . . . . . .

Selective Screening Methods . . . . . . . . . . . . . . . . . . . . . . . . . . .

Biochemical Screening Methods. . . . . . . . . . . . . . . . . . . . . . . . .

Technologies To Prevent or Reduce Horizontal Gene Transfer

Debilitated Host Organisms . . . . . . . . . . . . . .

Disarmed or Nonmobile Vectors . . . . . . . . . .

Summary and Conclusions . . . . . . . . . . . . . . . .

Chapter 4 References. . . .

4-1. Luminescence From a

Geme . . . . . . .

Table

4-1. - Genetic

-.

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Figure

. . . . . . . . .

. . . . . . . . .

. . . . . . . . .

. . . . . . . . .

Tobacco Plant Containing the

Factors To Evaluate in Planned

Firefly

. . . . . .

Introductions

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77

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Luciferase

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Chapter 4

Genetic Considerations

The safety questions raised by the planned introduction of genetically engineered organisms

are not unique to such organisms. Yet the introduction of these organisms raises some safety

questions that are quite different from the questions of physical containment on which previous

discussions of the safety of recombinant DNA research have focused. And though the intimate interplay between the genes of an organism and

the environmental parameters that govern the

way the genes are expressed makes most separations of genetic and environmental factors difficult, such divisions make the issues easier to examine. This chapter focuses primarily on genetic

issues, particularly as they relate to the potential

for movement of engineered genetic material beyond the intended host. Most genetic factors are

either important primarily as they relate to this

potential, or are more clearly relevant in an ecological context, and are thus discussed in chapter 5.

The migration of genetic material, or horizontal transfer, is the passage of genetic material

from one organism to another through a mechanism not involving specialized reproductive

cells (i.e., nonsexual gene transfer). In bacteria,

it is the transmission of genetic material from one

contemporaneous bacterial cell to another, by any

of several means. OTA assumes that genetic material introduced into a host in which it does not

naturally occur has some finite probability of

migrating to a nontarget organism. What is that

probability? How can the movement of the genetic

material be observed? What are the potential consequences of horizontal gene transfer? And what

steps can be taken that would limit the frequency

or mitigate the potentially adverse consequences

of horizontal transfer?

An OTA workshop, convened in collaboration

with the National Science Foundation, examined

these and other questions surrounding genetic issues in the planned introduction of genetically

altered organisms. This chapter summarizes some

of the factors that could influence the frequency

of horizontal gene transfer after the planned introduction of recombinant organisms and examines technologies designed to affect horizontal

transfer. Most of this chapter is relevant primarily to microbes and much less relevant to higher

organisms such as plants or animals, unless

specified.

WHAT IS KNOWN ABOUT HORIZONTAL TRANSFER OF GENES?

Genetic material probably does not often move

across large evolutionary distances, between

organisms only remotely related. When gene

transfer does occur, it appears to take place via

a limited number of mechanisms. Different types

of organisms, such as bacteria and plants, share

some mechanisms for genetic transfer, while other

mechanisms are specific or unique to particular

organisms (2,14,15).

The different types and mechanical details of

gene transfer have been discovered and examined

primarily in controlled laboratory situations. Gene

transfer between bacteria under laboratory conditions has been widely described, and there is

evidence that transfer in natural ecosystems (e.g.,

in soil, in aquatic systems, or on plant surfaces)

does occur (12). Horizontal transfer between

plants has not been well studied, and no conclusive data exist to indicate that it occurs in nature.

But nonsexual genetic exchange involving the insertion of bacterial material into plants is well documented. Gene transfer has been investigated and

described in invertebrate systems, particularly insects. Evidence from the evolutionary record suggests that some rare horizontal transmission of

genetic material has occurred between mammalian species. Although there is no firm evidence

that genes are passing back and forth between

diverse groups of organisms, there are instances

that warrant further investigation.

Although several specific systems of genetic

transfer have been studied, they probably represent only a subset of what actually occurs in nature. In fact, since these systems have been

71
72

selected for intensive research because of their ●

ease of handling, the likelihood of producing rapid

results, and their accessibility to existing research

methodologies, their role in horizontal gene transfer in nature maybe overestimated. Indeed, many ●

barriers to gene transfer exist in natural systems.

Thus, many questions remain to be answered

about gene transfer outside the laboratory, including:

What are the genetic and environmental conditions under which novel information could

be incorporated into a foreign genome and

subsequently expressed?

Do populations of organisms limit incursion

of new genetic material, and if they do, by

what means?

● How extensively do the gene transfer mechanisms observed in the laboratory operate in

nature?

WHAT GENETIC CONSIDERATIONS MUST BE EVALUATED IN

PLANNED INTRODUCTIONS?

The planned introduction of a genetically engineered organism raises three issues of immediate concern. First, if gene transfer does occur,

will the new genetic information be maintained

and expressed? Second, what is the potential extent of horizontal transfer of manipulated genetic

material? And third, if the modified organism, or

the inserted DNA it contains, moves beyond the

point of introduction, how will it affect the surrounding populations or communities of plants,

animals, and microbes? This issue, regarding ecological considerations, is discussed in chapter 5.

The first two questions, of horizontal transfer and

expression, are considered here.

Some commentators have maintained that if the

gene in question will not move to other organisms then there is no need to worry about potential consequences of its introduction. others maintain that if the modified organism or gene of

interest would not cause problems even if it

moved, then the exercise of estimating transfer

probability is unnecessary. Both issues should be

addressed in assessing potential consequences of

a proposed introduction experiment (see ch. 6),

although in some cases not enough is known about

the life histories of organisms that could be involved to make such hazard estimates possible.

But a very low probability of transfer multiplied

by a moderate probability of expression and resultant hazard if transfer occurs is a different situation than if both probabilities are very low. By

the same token, a significant probability of benefit could offset all or part of any potential risk.

Many factors influence the magnitude, frequency, stability, and effects of horizontal gene

transfer to nontarget organisms. Identifying these

factors is necessary if scientists, corporate administrators, and government regulators are to

evaluate environmental applications of genetically

engineered organisms. Table 4-1 lists the minimum

factors that must be considered, which are discussed in the next section.

Predicting the Potential Effects

of Horizontal Transfer

Can generic rules be discovered that would help

distinguish a condition of low probability of horiTable 4-1.—Some Genetic Factors To Evaluate in

Planned Introductions

Possible method of

manipulation Factor

Organism choice or design Gene

Vector

Construct

Host organism

Recipient organism

Population manipulation Survival of released organisms

Population density of host

Other means Presence of potential nontarget organisms

Density of potential nontarget organisms

Selection pressure

SOURCE” Office of Technology Assessmnl, 1988
73

zontal gene transfer from one of high probability? What types of accessible information yield

likely estimates of the magnitudes of horizontal

gene transfer? These questions are difficult to answer with precision.

An analysis of the magnitude of horizontal

gene transfer must include at least two components:

Ž an estimate of the frequency of gene transfer from introduced to nontarget organisms,

and

Ž an estimate of the genetic distance between

the original organism and the nontarget

species.

The consideration of both intrinsic and extrinsic factors can help assess the likely extent of horizontal gene transfer. Intrinsic factors, which are

elements of molecular biology, include:

●

●

●

●

the host organism used in the application

(e.g., plant or micro-organism);

the gene being manipulated (e.g., gene conferring pesticide resistance or ice-nucleating

activity);

the vector introducing the gene into the host

organism (e.g., a plasmid or virus); and

the construct, or final configuration of the

new genetic material within the host organism, which will govern expression and stability of the gene product.

Extrinsic factors, which are elements of ecology,

include:

the survival of the released host organism,

the presence of potential nontarget recipients of the gene and the evolutionary relationship between the host and potential nontarget organisms,

the population densities of the engineered

host and the potential nontarget recipients

in the environment, and

the selection pressures to maintain the new

gene in either population.

By influencing the magnitude of horizontal gene

transfer, these extrinsic factors become integral

to any examination of genetic considerations of

environmental release.

Intrinsic Factors

The impact of intrinsic factors on horizontal

gene transfer cannot be measured by simple

descriptive information about the host, gene, vector, and construct. A number of principles help

explain and predict the behavior of genes. Before

estimating the frequency of horizontal transfer

in a system, the natural histories of each component must be understood. The information should

include, but not be limited to, how the gene is

expressed in different environments, both genetic

and ecological; the behavior of the vector in different hosts; and the different life stages, if any, of

the host.

Host

It is important that the micro-organism, virus,

fungus, plant, or animal used as the host be well

understood, and its life cycle well studied. Perhaps most important, the mechanism(s) by which

the organism transfers genetic material in the laboratory should be identified. For instance, one

class of bacteria (called gram-negative) usually uses

plasmids or phages to facilitate genetic exchange.

Another class (gram-positive) uses the direct exchange of DNA segments as an important mechanism of gene transfer.

Although the bacterium Escherichia coli is well

understood, less is known about genetic exchange

by bacteria outside the laboratory, especially in

soil. In some instances, nondebilitated bacteria are

being developed for planned introductions despite

the paucity of information on host survival,

genetics, and population structure. Some of these

organisms may survive and function for long

periods in their new environment (13). Without

a well-developed natural history of host organisms, it is impossible to evaluate the genetic

and ecological implications of a planned introduction. Substantial experience with past

microbial introductions indicates, however, that

even when introduced bacteria survive, they do

not come to dominate the host community,

The presence of cryptic genetic material (e.g.,

cryptic plasmids) is a host characteristic that

merits special consideration. Cryptic genetic ma-
—

74

genetic material could provide the mechanism for

an engineered gene to be transferred from the

host to a nontarget organism. This possibility

makes it important that the life history of the

I

I

@ 1986 by Sydney Harris, American Scientist Magazine

“There is no problem. Any damage caused by the

nuclear accident can easily be remedied by genetic

engineering. ”

terial appears to have no assigned function and

is often assumed to be inactive. But its function

may depend on environmentally induced stimuli,

a condition that could make it appear nonfunctional in the laboratory. A gene on a cryptic plasmid, for example, might be expressed only under

starvation conditions, a common condition of bacteria in nature but not in the laboratory.

One species of Yersinia provides an example of

differential gene expression. This bacterium carries a plasmid that produces four or five important gene products only when the organism is

growing within its natural environment. Another

example can be seen in the difference between

E. coli in the test tube and in its natural habitat,

the gut. Some E. coli plasmids code for adhesion

factors that allow the bacterium to colonize the

gut. These plasmids are expressed only when the

bacterium is in the gut. Thus, genetic material that

appears to be cryptic in the laboratory could have

important functions in nature. So it is theoretically possible that a seemingly dormant piece of

of bacteria-carrying cryptic plasmids, at least in

situations where it is imperative to avoid the possibility of gene transfer.

On the other hand, the natural histories of many

host organisms are well known. One such host

is Pseudomonas fluorescent. Scientists have proposed using this bacterium, altered to carry the

delta-endotoxin gene from Bacillus thuringiensis,

to protect corn roots from the black cutworm.

The toxin kills the cutworm that feeds on the corn

rootlets. The P. fluorescent host was chosen because it has been well studied and is easily identified. Since the toxin gene has been inserted into

a new host organism, however, the probability

and frequency of the gene being transferred out

of the engineered Pseudomonas is a valid question. Do the mechanisms that 13. thuringiensis uses

to exchange genetic material differ from those of

P. fluorescent? Is the frequency of gene transfer

different between the two, or do they typically

exchange genes with the same or different species? Do restriction enzyme systems in potential

nontarget recipients reduce the probability of

transfer of intact DNA? Host-related questions

such as these may be important in assessing

genetic considerations of planned introductions.

Gene

Ideally, planned introduction experiments would

involve genes that have a well-understood natural history as well as host organisms that have

been studied thoroughly. An extensive natural history would help determine whether potential new

interactions between the gene and the environment could result from the gene’s presence in a

new host microenvironment. How specific should

or could applications for approval of planned introduction field tests be about gene-environment

interactions? Can any novel expression of phenotype occur? Unfortunately, these questions are

impossible to answer, because they require scientists to predict and quantify the occurrence of

rare and idiosyncratic events. Only gradually increasing experience will start to provide answers.
75

Again, the toxin gene of B. thuringiensis is a good

example of a gene from an organism with a wellcharacterized natural history (l). The naturally

occurring bacterium and derived materials have

been used for decades. They are now available

in over 410 different products, in 13 formulations

(e.g., powder, pellet, or solution) to apply the toxin

in garden, agricultural, and forestry settings (6).

In many areas containers of B. thuringiensis spores

can be purchased at garden stores. Tons of the

bacterium have been applied to agricultural and

forestry lands. Despite intensive searching, scientists have unearthed no evidence to date that

either the endotoxin gene has escaped from the

Bacillus and been expressed in other microbes,

or that the toxin from this strain (var. kurstaki)

has any effect on organisms other than Lepidoptera and closely related insects.

Vector

Vectors are the means by which genetic material is shuttled between organisms. Just as it is

necessary to have a well-characterized host and

gene, it is important to use a vector with well understood characteristics. Important factors include

the vector’s ability independently to initiate or sustain horizontal gene transfer, its need for outside

help to move information, and its degree of mobility or the extent of its host range.

Construc t

An important factor affecting the probability

that an inserted gene might move from an altered

host to a nontarget organism is the final configuration of the new gene in the host—i.e., the DNA

structure at the site of gene insertion. For instance,

inserting a gene into a chromosome minimizes

subsequent gene movement, especially compared

with inserting it into a plasmid. The source of the

regulatory sequences controlling expression of the

inserted material is also important and plays a major role in limiting the field of potential nontarget

recipients.

Genetically engineered “ice-minus” bacteria also

illustrate the importance of construct to the likelihood of horizontal gene transfer. This bacterium

is created by removing a gene found naturally in

Pseudomonas, Erwinia, and other bacteria, a construction that decreases the probability of horizontal gene transfer.

The transfer of a deletion—in this case, essentially a missing gene—to a nontarget organism cannot impart a new capability to the recipient in the

same way that acquiring a novel structural gene

can, as in the case of the B. thuringiensis toxin

gene. So even if the altered genetic material is

transferred beyond the host, it cannot add to the

nontarget recipients the ability to produce a new

gene product. Deletions can, however, alter the

relationships of the host species to other organisms with which it interacts, a change that could

be important under some circumstances.

Extrinsic Factors

The extrinsic factors that strongly influence the

likelihood and magnitude of horizontal gene transfer are an integral part of the environment into

which the engineered organism is introduced. The

expression of the trait, the intended environment,

and other environments that the engineered

organisms could encounter must be analyzed for

their possible impact.

Survival

A key determinant of potential horizontal transfer is the ability of the introduced organism to

establish and reproduce itself in its new habitat,

and to stably express the engineered trait, Unfortunately, little information exists on the potential survival, establishment, growth, and subsequent genetic transfer ability of engineered

organisms placed as competitors to indigenous

organisms in a natural environment (13), though

most evidence suggests survival is most likely to

be diminished. Laboratory conditions are artificial and differ significantly from those encountered by organisms in their native habitat. For example, the mean generation time for many

bacteria in soil is about six months (although this

figure varies widely for different soil organisms

and with the season), compared to one hour or

less under laboratory conditions. The time of year

and the local qualities of individual introduction

sites could also affect survival significantly.

In one experiment, naturally occurring P.

fluorescent were isolated from corn roots and
76

given genetic markers to allow them to be detected

at a later time. The organisms were then reinoculated onto the corn roots at a moderate density.

During the following growing season it was difficult and in some cases impossible to re-isolate the

marked organisms, Thus, a soil system (and perhaps other natural habitats) might not contain

enough nutrients to allow measurable survival of

laboratory-adapted microorganisms. Certainly for

genetically engineered micro-organisms (and perhaps other organisms), the problem will likely be

less one of persistence and gene transfer than of

survival to perform the job for which they were

designed.

t Potential Nontarget Recipients

For horizontal gene transfer to take place, a compatible recipient must be available. The most likely

recipient is an organism genetically similar to the

engineered host. The probability of transfer generally declines as evolutionary relatedness decreases. Restriction enzyme systems that degrade

evolutionarily unrelated “foreign” DNA are common among bacteria.

Information about the natural history of potential nontarget organisms in the environment, however, is scarce—less than for laboratory-engineered

organisms. In the case of bacteria for agricultural

applications, potential microbial recipients in soil

are of interest. Yet only about 10 percent of the

1 microbial species in soil can even be cultured in

 the laboratory.

I Horizontal transfer of genetic material between

higher organisms is less likely than that between

simpler ones. However, gene transfer via sexual

recombination among these organisms could be

an important problem. In particular, genetic movement via natural sexual transfer from crop plants

(e.g., engineered to be herbicide resistant) to related weedy species could occur. Such problems

are neither new nor unique to engineered plants,

however (see ch. 5), and the processes involved

are understood.

Density

Important factors affecting the magnitude of

horizontal gene transfer are the absolute densities of the introduced and recipient organisms.

According to laboratory research with bacterial

systems, the rate of transmission seems to be

proportional to the product of the densities of the

donors and recipients.

In the case of micro-organisms, it appears that

the numbers of naturally occurring nontarget recipients in the environment (e.g., in soil or water)

are low-considerably lower than the concentrations necessary for efficient gene transfer in the

laboratory. For instance, among organisms that

are well studied, the number of naturally occurring organisms in fertile soil is normally at least

an order of magnitude lower than concentrations

of bacteria necessary for horizontal transfer in

the laboratory.

Density can also be affected by the method used

to introduce an engineered organism. Additionally, the timing of the planned introduction can

affect the density of both the engineered organism and potential nontarget recipients. But keeping introduction densities low to avoid gene transfer may not be consistent with an effective

introduction, since high initial density and survival may be required for efficacy.

Selection Pressure

The probability that new genetic material will

persist, be expressed, and increase in frequency

in nontarget populations if transmitted is at least

as important as the probability of horizontal gene

transfer itself. Selection pressure is the major determinant. A low probability of positive selection

—i.e., little likelihood of the persistence of the new

material—is usually the desirable outcome.

Selection pressure is determined by a combination of factors, including the trait encoded by

the engineered gene, the potential recipients, and

the value of the trait in the introduction environment. Because environmental conditions are generally harsh and stringent (e.g., inadequate nutrients for growth, and suboptimum temperature

conditions), selection pressure is crucial. Under

usual conditions (i.e., the gene product does not

confer a selective advantage), even a moderate

amount of new DNA assimilated by an indigenous

soil or water microorganism may impose enough

of an energy drain that the organism will be

selected against in competition with others that
77

do not carry additional DNA. However, different

introductions will vary with respect to the important selection pressures, and they must be

evaluated separately.

Even a low horizontal transfer rate can establish the trait in a new species if assisted by strong

selection pressures. Although some individuals

point to the rapid spread of antibiotic resistance

in gonococcus as an example of the widespread

TECHNOLOGIES TO MONITOR

Beyond the intrinsic and extrinsic factors that

could affect the magnitude of horizontal gene

transfer in environmental applications, it is important to examine risk management methods that

could be used to monitor both the dispersal of

altered organisms and the movement of genetic

material. Because proposals to introduce genetically engineered organisms are still new, detection or tracking methods are not highly developed.

Experience (e.g., with past introductions of rhizobial or plant pathogenic bacteria) suggests that

although such tracking methods will be needed

in the future, their current level of development

presents more inconvenience than danger.

An important distinction in monitoring is the

difference between tracking the organism and

tracking the gene or construct of interest that the

organism carries. Improved methods to do both

have been identified as one of the major unmet

research needs in this area (see ch. 6). Some tracking technologies are now available.

Selective Screening Methods

One tracking method is based on the ability of

researchers to mark a host organism’s chromosome with genetic characteristics, such as antibiotic resistance genes or nutritional markers, that

will confer an advantage to the organism when

placed under specific conditions in the laboratory.

These selective methods, principally used with

micro-organisms, increase the probability that an

investigator can isolate the test organism from the

environment if it has persisted.

While useful in the laboratory, markers that

could confer an unintended selective advantage

problems that can occur when genes are horizontally transferred, it is important to realize that

intense selection pressure exerted by indiscriminate and subtherapeutic antibiotic use, especially

in foreign countries, was probably the overwhelming cause of this phenomenon. The development

of penicillin resistance by gonococcus illustrates

the power of selection pressure to overcome such

seeming obstacles as low rate of transfer.

HORIZONTAL GENE TRANSFER

in the environment, either to the host organism

or nontarget recipients, should be avoided if possible, and carefully evaluated when used. One

study concluded that “it is essential to choose antibiotics which are not in use in humans or animals, since resistance to clinically useful antibiotics is a major public health problem” (10). The

example of penicillin-resistant gonococcus, cited

earlier, underscores this point. But even the largescale introduction into the environment of genes

for resistance to nontherapeutic antibiotics should

be carefully evaluated. Some resistance genes

could mutate to counter whole families of related

antibiotics. The kanamycin resistance gene, for

example, could acquire the ability to neutralize

newer antibiotics derived from streptomycin.

Some individuals, however, argue that the introduction of resistance genesis unlikely to cause

problems, especially inland applications. The argument is based on two considerations, both involving micro-organisms. First, many resistance genes

are already present in soil micro-organisms. In

fact, this background of resistance could hinder

tracking efforts, a problem that will almost certainly require the use of multiple selective markers. Second, studies of root ecology have long

involved the use of antibiotic resistance with no

apparent adverse effects.

Technologies using selective methods to track

the genetically engineered gene itself are under

development and promising approaches have been

designed. The antibiotic resistance strategy puts

a resistance marker near the gene of interest. The

antibiotic could be used to recover any cells containing the resistance gene. In most cases, the gene

of interest—the inserted gene—would travel with
78

the antibiotic resistance marker. So obtaining and

quantifying cells that are antibiotic-resistant would

allow the measuring of horizontal gene transfer

to nontarget species. Another approach avoids the

use of antibiotics and employs a metabolic marker

such as lac, which brings the capacity for metabolism of lactose, as a convenient, innocuous, but

effective tracer gene. The km gene is inserted close

to the gene of interest so that it may serve as a

linked marker.

Biochemical Screening Methods

A different approach to the tracking problem

employs gene probes constructed through recombinant DNA technology. A segment of DNA that

is complementary to the gene, or DNA sequence,

of interest serves as the probe. The segment is

labeled with radioactivity, a specific dye, or other

tag that can be easily detected in the laboratory.

A sensitive method, this gene probe technique may

identify both host and nontarget recipients of labeled material. Similarly precise identification is

also possible with antibody probe analyses derived

from monoclinal antibody technology.

To apply these methods to bacteria or viruses,

the organisms would be isolated from the environment and their DNA extracted and tested with

the specific gene or antibody probe. With plants,

leaves and other parts would be obtained and their

DNA extracted and tested with the probe in the

laboratory. By binding to an organism’s DNA, the

probe reveals that the organism carries the gene

of interest. Such probes allow the detection of an

inserted gene regardless of its position in the host’s

or recipient’s genome. In contrast, the selective

screening method just discussed becomes useless

if the inserted gene becomes separated from a

closely linked selection marker.

One disadvantage of the gene probe is that it

provides no means of discriminating between samples that should be tested and those that should

not. Everything that grows out of a sample (e.g.,

micro-organisms from the soil or a river, or plants

from a wide area) must be screened. Furthermore,

as mentioned earlier, many native micro-organisms cannot be cultured in the laboratory. Thus,

these probe methods of tracking will probably be

more useful to detect and monitor the presence

of host organisms than to quantify horizontal gene

transfer.

Research projects based on the gene probe concept are now being funded by the Environmental

Protection Agency. The general applicability of

biochemical monitoring appears promising. In the

case of soil micro-organisms, extracted DNA must

be purified sufficiently to meet laboratory conditions for the test to be accurate. In water applications, enormous volumes of water often must be

processed to obtain test samples.

A related biochemical tracking method uses the

luciferase gene cloned from fireflies. This gene

codes for a light-emitting protein, luciferin, and

has been inserted into plants and cultured plant

cells that now “glow in the dark.” Although the

presence of the luciferase gene can be detected

through the probe methods just described, it can

also be detected easily through image intensifying video equipment or by contact exposure to

photographic or x-ray film (see figure 4-1) (11).

Figure 4-l.— Luminescence From a Tobacco Plant

Containing the Firefly Luciferase Gene

SOURCE: D.W. Ow, K.V. Wood, M. DeLuca, J.R. deWet, D.R. Helinski, and S.H,

Howell, Science 234:856-859, 1986.
79

Using the firefly gene as a marker could be a fast, the host organism, however, and its utility is thereeasy, and useful method to track genetically engi - fore likely to be limited.

neered organisms. It is very energy-intensive for

TECHNOLOGIES TO PREVENT OR REDUCE HORIZONTAL

GENE TRANSFER

In addition to the technologies being developed

to track host organisms and genes, methods are

being developed that manipulate intrinsic factors

so that introduced organisms have:

. a lower probability of persisting after introduction,

. a lower probability of transferring genetic material, or

● both.

Methods to prevent or reduce horizontal gene

transfer are straightforward. The genetics and

biochemistry of conjugal transfer have been well

studied. By mutagenesis or genetic engineering,

the capability for mobilizing DNA for transfer, and

the genes specifying the necessary cellular apparatus for the transfer, can be removed from a plasmid. The plasmid can be further debilitated so

that it is only poorly mobilized in the presence

of another, potent plasmid. Such disabled plasmids are not capable of detectable horizontal gene

transfer, and these disabled plasmids are commonly used at present in genetic engineering in

bacteria.

Although the application of disabling methods

may be an important component of planned introductions of genetically engineered organisms,

the specific type of organism involved must be

considered. Even the most active plant vectors,

for example, probably have a lower likelihood of

horizontal transfer than the least active bacterial

vectors. Furthermore, it appears that genetically

altered organisms that derive their utility by being deprived of a trait (i.e., a deletion) are less likely

to be able to produce problems via gene transfer,

although this might not always be the case (3,9).

Experience in working with recombinant DNA

organisms in the laboratory provides some examples of success in restricting unintended gene

movement by disarmament measures, These approaches, specifically the use of crippled bacteria and plasmids, have served as the starting point

in developing ways to prevent or reduce horizontal gene transfer.

Debilitated Host Organisms

The degree to which a host organism should

be debilitated will, again, depend on its intended

application. In the case of a bacterium that will

be used to degrade a toxic chemical, it might be

prudent to use a self-destructing organism, since

the bacterium only need persist as long as the pollutant is present. On the other hand, if the bacterium were designed to protect a plant from an

insect pest, the organism persistence in the soil

might be desirable (but see ch. 5).

One of the earliest attempts to construct a debilitated organism arose from the original questions surrounding the first uses of recombinant

DNA technology. Although several studies had

established that the organism initially used in recombinant DNA experiments (E. coli K-12) did not

colonize the human intestinal tract (even after ingestion of billions of organisms by volunteers), a

severely crippled strain of E. coli K-12, designated

x

1776 , was developed. This further debilitated

derivative was, however, quite difficult to work

with even in the laboratory. With experience, the

original K-12 strain has proved to be an extremely

successful and effective form of biological containment. The use of debilitated organisms in field

tests, however, might compromise the value of

the test, and therefore may not be a generally

desirable approach.

Another approach sometimes suggested for reducing the chance of gene movement is to engineer restriction systems, common defense systems

in naturally occurring bacteria, into a host bacterium. Restriction enzymes degrade unprotected

DNA, so that foreign DNA from a donor is unable

to infect the host. They are common enough in
80

natural populations of bacteria that they can be

expected to play a significant role in deterring the

transfer of genes from introduced engineered

organisms. In addition, such naturally occurring

restriction systems might be adapted to help inhibit transfer of the inserted gene out of the engineered host, or otherwise limit its function or persistence. At present, such systems are not well

developed, but they hold substantial promise.

Disarmed or Nonmobile Vectors

In addition to engineering crippled host organisms, more stable vectors— those that would have

I little probability of facilitating genetic movement

—are being developed. In particular, efforts are

focused on obtaining microbial and viral vectors

that are “escape-proof.”

The concept of a debilitated host microorganism

(e.g., E. coli K-12) was also applied to the development of a vector for that system. Plasmid pBR322

was isolated and has been used as a vector for

transferring engineered genes in the laboratory.

The plasmid is incapable of self-initiated transfer

and is also poorly mobilizable. It is therefore considered safe; it has a low probability of being transferred to bacteria indigenous to natural habitats,

including the human gastrointestinal tract. Similarly crippled vectors have been developed for use

in insects and for mammalian genetic engineering.

Another precaution suggested by the gonococcal resistance example (see box A in ch. 1) is to

I

reduce or eliminate the use of mobile transfer elements in engineered organisms. Since some vectors are clearly more mobile than others, using

disarmed versions of these vectors, or avoiding

their use entirely, would reduce the probability

of horizontal gene transfer.

A disarmed vector (a transposable element) was

the approach used in the insertion of the toxin

gene into P. fluorescent. This technique appears

to be successful, and the application to field test

the organism is pending. Experiments show that

it is unlikely that the nonmobile transposon will

be excised (7,8).

Finally, an EPA research group is attempting

to construct a “suicide” bacterium designed to persist in the environment only as long as it is needed.

The organism is a bacterium that contains a vector (in this case a plasmid) that will self destruct

in the absence of the toxic substance it has been

designed to clean up. A better name for this technique might be “suicide plasmid,” since the main

purpose is to destroy the vector DNA before it

transfers to another host. Other groups are also

working on different means to similar ends (4).

However, the demonstrated ability of free DNA

to sometimes maintain its integrity in soil or water

creates a potential problem. If the cell were killed

before the plasmid had self-destructed, and the

plasmid with its inserted gene remained intact,

it is possible that the plasmid could enter another

cell.

SUMMARY AND CONCLUSIONS

The planned introduction of genetically engineered organisms (chiefly bacteria and plants)

stands as the next research step in the anticipated

biotechnological revolution. Although genetically

altered organisms isolated through traditional

genetic methods have been widely used in the

environment for decades, the prospect of widespread application of genetically engineered

organisms has heightened the concern of some

that increased problems may arise. “The implication for R-DNA-engineered organisms is that largescale or sustained applications might have consequences different from small-scale or single

applications . . . the cumulative probability of undesirable effects resulting from repeated applications or frequent introductions must be considered” (5). Another potentially important

question about the planned introductions concerns the possibility that an introduced organism

might transmit its novel genetic material to nontarget hosts, resulting in unintended and possibly adverse consequences.

Most of what is known about horizontal gene

movement has been discovered in laboratory

studies. Little information is available on how the
81

phenomenon occurs in nature. There appear to

be a limited number of gene transfer mechanisms;

research has revealed that different types of

organisms share some mechanisms for genetic.

transfer. Genetic material is not generally thought

to transfer across large evolutionary distances,

however, and there are numerous impediments

to gene transfer, even between closely related

species.

For regulators to assess the potential genetic impact of an engineered application, several factors

must be evaluated for their effect on horizontal

gene transfer: intrinsic factors, such as the host

organism, gene, vector, and construct, that are

elements of the molecular techniques used to create the engineered organism; and various extrinsic factors that are elements of ecology, including survival, potential nontarget recipients,

density, and selection pressure. Several methods

can now be used not only to monitor survival of

introduced organisms and genes, but also to reduce or prevent horizontal gene transfer.

Generic factors that can serve as a framework

for regulation can be described. Technological advances exist or are being developed to protect the

CHAPTER 4

1. Aronson, A. I., Beckman, W., and Dum, P., “Baciilus

Thurin&”ensis and Related Insect Pathogens,”

Microbiological Reviews 50:1-24, 1986.

2. Dixon, B., En~”neered Organisms in the Environment.- Scientific Issues, Lay Summary (Washington,

DC: American Society for Microbiology, 1985).

3. Lindemann, J., Warren, G.J., and Suslow, T.V., “IceNucleating Bacteria, ” Science 231:536, 1986.

4. Molin, S., Klemm, P., Poulsen, L. K., et al., “Conditional Suicide System for Containment of Bacteria

and Plasmids, ” BioTechnolo~ 5:1315-18, 1987.

5. National Academy of Sciences, “Introduction of Recombinant DNA-Engineered Organisms Into the

Environment: Key Issues” (Washington, DC: National Academy Press, 1987).

6. National Pesticide Information Retrieval Service,

‘(Data Bank Search on Baci]]us thuringiensis Based

Pesticide Products, ” personal communication from

James White to L.V. Giddings, OTA, Apr. 16, 1987.

7. Obukowicz, M. G., Perlak, F. J., Bolten, S. L., et al.,

“IS050L as a Non-self Transposable Vector Used

public and environment from any unintended consequences of introducing altered organisms. Some

introductions merit closer scrutiny than others,

and OTA finds that evaluation of proposed applications to introduce into the environment

genetically engineered organisms which are

believed to carry some element of risk should

proceed on an adaptable, case-by-case basis,

at least until knowledge has been accumulated

to make more general reviews feasible. With an

adaptable, case-by-case review of such planned

introductions, not only the current spectrum of

genetically engineered organisms, but kinds as yet

unanticipated should be able to be tested in the

environment without unreasonable risks. The current range of genetically engineered organisms

seems to have a low probability of creating problems, particularly via the horizontal transfer of

genetic information to nontarget recipients. However, this does not mean there are no risks at all.

Careful regulation and enforcement can guard

against potential environmental or public health

problems and protect the biotechnology industry from the backlash and loss of credibility and

confidence that a severe problem could precipitate.

REFERENCES

to Integrate the Bacillus thurin~”ensis 13eltaendotoxin Gene Into the Chromosome of Root-colonizing I%eudomonads, ” Gene 51:91-96, 1987.

8. Obukowicz, M. G., Perlak, F. J., Kusano-Kretzmer,

K., Mayer, et al., ‘(Tn5 Mediated Integration of the

Delta -Endotoxin Gene From Bacillus thuringiensis

Into the Chromosome of Root Colonizing Pseudomonades,” .Journa) of Bacteriology 168:982-989,

1986.

9, Odum, E.P., “Biotechnology and the Biosphere)” Science 229:1338, 1985.

10. Omenn, G. S., “Controlled Testing and Monitoring

Methods for Micro-organisms,” The Suitability and

Applicability of Risk Assessment Methods for Environmental Applications of Biotechnology, V.T.

Covello, and J.R. Fiksel (eds.) (Washington, DC: National Science Foundation, 1985).

11. Ow, D. W,, Wood, K. V., DeLuca, M., et al., “Transient and Stable Expression of the Firefly Luciferase Gene in Plant Cells and Transgenic Plants, ” Science 234:856-859, 1986.
82

12. Shaw, P.D., “Plasmid Ecology, ’’l%nt-A4icrobe Inter- 14. U.S. Congress, Office of Technology Assessment,

actions—Molecular and Genetic Perspectives, T. Commercial Biotechnology: An International AnalKosuge and E. W. Nester (eds.) (New York, NY: Mac- ysis (Elmsford, NY: Pergamon Press, Inc., 1984).

Millan Publishing Co., 1986). 15. U.S. Congress, Office of Technology Assessment,

13. Stotzky, G., and Babich, H., “Fate of Genetically- Impacts of Applied Genetics: Micro ~rganisms,

Engineered Microbes in Natural Environments,’’Re- Plants, and Am”mals, OTA-HR-132 (Washington, DC:

combinant DNA Technical Bulletin 7(4):163-188, U.S. Government Printing Office, April 1981).

1984.


Chapter 5

Ecological Considerations

In 1987, a report by the National Academy of

Sciences stated “an urgent need for the scientific

community to provide guidance to both investigators and regulators in evaluating planned introductions of modified organisms from an ecological perspective” (39). This chapter incorporates

such a perspective and focuses on a number of

ecological issues relevant to the planned introduction of genetically engineered organisms into the

environment.

The major concern associated with planned introductions stems from the potential for problematic ecological effects that are unintended or unforeseen. With appropriate regulatory oversight,

such effects are unlikely to follow from any

planned introductions in the near future. If they

occurred, however, they might be felt at any

level—from the local population, through the community and ecosystem, to fundamental ecological processes—although the probability of such

disruptions decreases as their severity increases.

A number of ecological questions are explored in

this chapter, including the relevance of experience with introduced exotic organisms, the types

of disruptions to natural populations that could

take place, and the potential for effects on ecosystem processes of energy flow and nutrient cycling. Review of the data bearing on these questions suggests that there is some reason to be

cautious, but no cause for alarm at the prospects of planned introductions of genetically

engineered organisms into the environment.

GENETICALLY ENGINEERED ORGANISMS AND EXOTIC SPECIES

Studies of biogeography–the distributions of

plants and animals-demonstrate the presence in

most modern environments of nonnative or exotic organisms that evolved elsewhere. The number of these exotic species (microbes, plants, and

animals) is large, as a result both of natural processes of dispersal and deliberate and accidental

distribution aided by humans. No good data indicate what proportion of introduced organisms has

created ecological problems, although it is generally agreed to be small. Some scientists believe that

experience with exotic species provides an example of what might be expected from genetically

engineered organisms in planned introductions,

and that “the history of introductions is a history

of disasters that should not be forgotten lest it

be repeated” (23). Others argue that the best guide

is the experience with past introductions in agriculture of organisms produced by hybridization

and crossbreeding—a history of far more positive

results, and one in which negative consequences

have been met with a variety of existing control

and mitigation strategies. They point out that all

major crops in the United States are exotic species introduced from other regions of the world,

and that it is often important to separate the effects of planned introductions from those of accidental introductions. Although no existing database provides all the information needed to

answer questions in this area, there are several

different sources of relevant data.

Introductions of Exotic Species

A wide variety of reports have been published

on invasion or colonization by exotic species (16,

17,23,37,57). Some of the most quantitative data

available deal with insect introductions. One study

reveals an exponential increase in the number of

insect species introduced into the area of the 48

contiguous States from 1640 to 1977 (table 5-1)

(46). NO data are available on the number of potential insect introductions that failed to become

established, but it is assumed to have been far

larger than the number that succeeded (46, 56).

Of the 1,379 species noted as having been successfully introduced, some economic importance

is assigned to 1,089 of them (79 percent). This percentage is almost certain to be an overestimate

since insects with no economic impact draw scant

85
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86

attention and may inadvertently be excluded from

the total of successful introductions. The economic

significance of those introductions that were noted

is further broken down in table 5-1.

One-fifth of the introductions studied had some

beneficial impact; another fifth had no significant

impact. Two-fifths (41 percent) of the successful

introductions were of insects that turned out to

be minor pests. About one in five introductions

had severe, negative consequences (17 percent).

The majority of these negative effects were unexpected, because no such impacts were known

in the introduced species home ranges; the new

environment apparently lacked constraints that

operated in the original areas, If more had been

known about the life histories of these insects,

the kind of effects that followed their introduction to the new environment might have been anticipated.

One review of the history of plant and animal

introductions (57) concluded that in nearly 80 percent of the cases examined (678 of 854), introduced

species had “no effect whatsoever on species in

the resident community, or on the structure and

function of the community.” Other, more critical

reviews of the same primary data dispute this conclusion, attributing it to a peculiar interpretation

and a restricted reading of the data (16,23). Although debate continues, the ecological literature

is replete with examples of communities perturbed

by introductions, or of introductions invading and

further disrupting environments previously disTable 5-1 .—Economic Significance of Insect Species

Introduced to the United States, 1640-1977

Estimated total native insect fauna. . ..104,000 species

Total insect introductions

(1 percent of native fauna) . . . . . . . . . 1,379

Beneficial introductions:

Deliberate. . . . . . . . . . . . . . . . . . . . . . . . 153

Accidental . . . . . . . . . . . . . . . . . . . . . . . 134

Total . . . . . . . . . . . . . . . . . . . . . . . . . . . . 287 (20.80/o)

Economically unimportant introductions 290 (21.030/o)

Minor pests introduced . . . . . . . . . . . . . . 566 (41.04°/0)

Important pests introduced:

Expected to be pests. . . . . . . . . . . . . . 80 (5.80/o)

Not expected to be pests . . . . . . . . . . 156 (11.310/0)

Total . . . . . . . . . . . . . . . . . . . . . . . . . . 236 (17.1 1 0/0)

SOURCE. R I Sailer. “Our Immiarant Insect Fauna.” ESA Bu//etin 24:3-11, 1978.

turbed. Most ecologists agree that successful introductions, while representing only a small portion of the total usually have some effect on

communities in the” host environment.

Introductions into natural systems are most

often successful where the host system has been

previously disturbed (i.e., by human action or natural catastrophe such as volcanic eruption, severe

storms, or floods) or is a “simple” or “disharmonic”

system such as those found on oceanic islands.

Introductions with the most serious consequences

usually involve host systems or organisms that

meet one or more of the following criteria (45):

●

●

●

Environments lacking potential preda=

tors, natural competitors, or similar checks

are vulnerable to disruption. Known examples of such disruption include herbivores

(e.g., goats) introduced to islands, or generalist organisms that feed or prey from high

positions in a food chain, and are thus unlikely to be checked by predation themselves

(e.g., mongooses, rats, or cats).

Ecological generalists, or species that can

exploit a variety of resources for differing requirements during their life cycles, are particularly capable of invading and colonizing.

Examples include organisms that can produce

offspring by laying eggs in many different

substances, and predators or parasites that

can prey upon or parasitize a variety of prey

or hosts.

Disturbed communities, or relatively “simple” or genetically homogeneous communities, are especially vulnerable to any invading species that might exploit available

resources more effectively.

These principles were abstracted from studies

of natural systems. Although they illustrate situations that are most likely to result in problems,

and therefore to be avoided where possible, their

applicability to the majority of planned introductions is quite limited.

Introductions of Agrcultural

Varieties

Most of the introductions of genetically engineered organisms planned for the foreseeable future are intended for agricultural settings. In such
87

systems—with a long history of introductions of

new crop cultivars, animal varieties in husbandry,

and microbes either for biocontrol of plant pathogens or inocculants for nitrogen fixation—a significant body of experience exists that is more

directly relevant, with better developed control

measures available, than is the case for introductions of exotic species.

The Agricultural Research Service of the U.S.

Department of Agriculture (USDA) maintains a

Plant Introduction Office that compiles data on

all plant material brought into the United States.

Since its inception in 1898, the office has recorded

over 500)

000 different plant samples (species and

varieties). From 1982 to 1986, an average of 8,270

new accessions per year were added to USDA

records (65). Over 90 percent of these were of

foreign origin, and the majority (over 80 percent)

had no measurable environmental or economic

impact, About 10 percent of the introductions

have proven to be valuable crops. A small number have become serious pests, such as Johnson

grass, water hyacinth, and veronica.

Agricultural introductions of plants are susceptible to a variety of control measures, such as herbicides, tilling, or crop rotation, in cases where

field performance is not acceptable. A plant is not

likely to escape, and the propensities for hybridization with adjacent weedy species are well

known (10), easily reviewed, and often subject to

existing methods of mitigation and control (7,8).

Genetically engineered agricultural organisms

are more likely to differ from parental strains in

only one or a few genes, and to be introduced

into a familiar environment, than they are to resemble introduced exotics, which usually consist

of a completely new genome in a novel environment (see table 5-2). The small number of genes

changed in most planned introductions should not

be overinterpreted as grounds for reassurance,

however, because in some cases single gene

changes are known to have affected the virulence

or host range of a parasite or pathogen (22)28)

32,56). Although this is of concern, such changes

are not common, and engineered organisms are

no more likely than nonengineered organisms to

be susceptible to them. Indeed, recombinant DNA

techniques enable engineered organisms to be

changed from parental strains with respect to the

genes controlling only one trait at a time. They

are therefore likely to differ from parental strains

less, and more precisely, than new varieties or

cultivars produced by historical methods of

hybridization and crossbreeding. This should permit a quicker understanding of any such shifts

in host range or virulence affecting engineered

organisms than was possible before, permitting

in turn the earlier application of mitigation or control measures.

The introduction of selected microbes for agricultural purposes has been carried out for nearly

a century (18,31). Substantial literature exists on

the ecology of microbial plant pathogens and their

introduction for biological control purposes (5,24,

48,62,64,67). Although uncertainties remain, this

experience gives good reason to expect that

planned introductions of genetically engineered

microbes can be carried out safely.

All this does not mean, however, that there will

be no problems with planned introductions of genetically engineered organisms. Indeed, in the long

term (10 to 50 years), unforeseen ecological conTable 5-2.—A Comparison of Genetically Engineered Organisms and Exotic Species

Characteristics Exotic organisma Engineered organismb

No. of genes introduced 4,000 to >20,000 1 to 10

Evolutionary tuning All genes have evolved to Organism has several genes it

work together in a single may never have had before,

package Most likely to impose a cost

or burden.

Relationship of organism Foreign Familiar, with possible

to receiving environment exception of new genes

a“Exotic organism“ is used here to mean one new to the habitat. b“Engineered organism” is Used here to mean a slightly modified (usually, but not alwaYs Via recombinant DNA techniques)

form of an organism already present in the habitat,

SOURCE: Office of Technology Assessment, 19S8.
88

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I

,

sequences of using recombinant organisms in agriculture are not only likely, they are probably

inevitable. But it is crucial to put this into perspective: It is difficult to describe a credible scenario that will lead to a problem that is different in kind from the problems created by, and

grappled with, in past agricultural practicees.

And while the adequacy of current regulatory

policies in dealing with existing agricultural practice may deserve examination, planned introductions of genetically engineered organisms do

not appear to bring with them such potentially

new problems that they require entirely new

regulatory approaches or more stringent

review.

In summary, for the majority of planned introductions of genetically engineered organisms presently being contemplated, the experience with

new agricultural varieties is a better model of

what can be expected than is experience from

introduced exotic species. While there are

grounds for caution, at least in the near term

this experience offers more reason to be reassured than alarmed.

POTENTIAL IMPACTS ON POPULATION OR COMMUNITY

STRUCTURE OR INTERACTIONS

Much of the concern over planned introductions

of genetically engineered organisms stems from

the difficulty of predicting reliably the consequences of any particular ecological perturbation.

In all cases, the ability to predict depends on the

degree to which the organisms and the initial conditions involved are understood, and in some cases

this is considerable. But the complexity of ecosystem processes and the numbers of different

species even in simple systems means that there

will always be uncertainties. Nevertheless, laboratory studies, greenhouse and small scale fieldtests,

and historical experience all suggest it is possible

to anticipate the likely consequences of introductions planned for the near future (over the next

5 years).

The potential ecological impacts most likely to

be noticed early involve effects on indigenous

organisms. Such effects are more likely to be seen

at the population or community level than at the

level of ecosystem process. Engineered organisms

that might cause such effects may be grouped into

four categories (29):

1. slightly modified forms of native organisms;

2. organisms existing naturally in the target environment but requiring continual supplemental support;

3. organisms that exist naturally elsewhere in

the environment, but that previously have not

reached the target environment (or have

reached it only at low levels); and

4. genuine novelties.

Slightly modified’ forms of indigenous organisms

have a relatively high (but still low) probability

of competing effectively with natives and thus of

perturbing populations of closely related or conspecific individuals. Most deliberate releases for

the foreseeable future are likely to be of this sort.

Despite some exceptions, it remains true that the

majority of mutations or genetic changes are

more likely to have negative than positive consequences for the competitive abilities of engineered organism& Thus researchers working to

produce organisms for planned introductions are

generally more concerned about the problems of

enhancing the competitive abilities of engineered

organisms so that they will survive to perform

their intended functions. When genetic changes

are directly aimed at enhancing competitive or

survival abilities the review process should explicitly recognize this, analyze the selective forces

involved, and review the potential implications.

Organisms existing naturally in the target environment, if they require continual supplemental

support, are even less likely to cause negative effects. The need for continual supplementation provides an effective means of control: stop the supplementation, and growth or function of the

introduced organism ceases. It would be logical

for planned introductions of this sort to be most
89

common in agricultural settings, but few are anticipated. Researchers and farmers are trying to

minimize the need for continual replenishment

(e.g., fertilizers for crop plants), not increase it.

This desire is one of the factors that has driven

agriculture to exploit biotechnology, in the hope

that products can be engineered to be easily managed and self-sustaining once introduced. The

need for continual supplementation might be exploited, however, to help control certain applications. But it must be realized that natural selection would be continually operating in ways that

would decrease the effectiveness of this type of

control, favoring genetic variants free of the imposed limitation.

The introduction of organisms that exist naturally elsewhere, but that have not previously

reached the target environment, presents the

highest probability of disrupting a community or

constellation of species in a given area. This category bears the most similarity to the introduction

of exotics, and is most likely to result in what have

been called “cascade effects” (discussed in the section on insect communities). And although most

introductions do not result in such severe effects,

dramatic and far-reaching disruptions of community structure can take place. Especially here,

though, perspective is important. Although some

planned introductions are indeed intended to allow growth in environments new to the organism,

appropriate regulatory oversight should minimize

risks. One example of a beneficial introduction

of this kind would be specific insect predators as

biocontrol measures aimed at severe pests. In the

past, biocontrol introductions that have been preceded by critical review have often been remarkably successful, with negative consequences rare,

but sometimes substantial (25,44).

The effects of genuine novelties are the most

difficult to predict because directly relevant experience is lacking. One of the chief problems here

is the lack of agreement on what would constitute a genuine novelty. Some contend that inserting a gene into an organism that would thus obtain an entirely new function or property, as for

example, Monsanto’s Bacillus thuringiensis (BT)

toxin containing pseudomonas, would constitute

a novelty. There is no general agreement on this,

however, worthy arguments being raised by both

sides. Fortunately, few planned introductions envisioned in the near future fall into such disputed

categories and it is broadly agreed that, for the

foreseeable future, most engineered organisms

will not be truly novel.

A clearer picture of the potentially negative consequences most likely from planned introductions

can be gained from a review of the types of introductions anticipated indifferent categories of communities.

Plant Communities

The largest number of modifications to plants

planned for introduction in the foreseeable future involves the insertion of genes to provide herbicide resistance. Most of the major companies

working in agricultural biotechnology are mounting efforts in this direction, studying crops for

which herbicides are useful in restricting competition from weeds. Such crops include tobacco

(more valuable, however, as a well understood

and malleable experimental system than as an end

product for agricultural use in and of itself), tomatoes, corn, rape, soybeans, and cotton.

Introducing herbicide resistance genes into

plants may bring ecological as well as economic

benefits by increasing the use of safer herbicides

and allowing their more precise administration.

Success could lead to significant increases in market share for particular herbicides, some of which,

however, are associated with significant environmental disadvantages.

Most of the herbicides to which resistance is

being engineered (e.g., glyphosate or sulfonylurea)

are environmentally “soft’’ -in other words, they

are not highly toxic to humans or vertebrates. In

many cases they affect only plants, since their target sites are metabolic pathways unique to plants.

Some of these herbicides degrade within days or

weeks to benign end products such as carbon dioxide and water. Work is also being done on inducing resistance to longer lasting, or more toxic,

herbicides, such as atrazine. Successful research

in such programs might well lead to increased use

of some herbicides with less desirable characteristics. The particular cost/benefit estimates will

vary with each herbicide and its qualities. Con63-220 0 - 88 - 4 : QL 3
93

sideration of such factors might be more appropriate in reviews for product licensing than in the

regulation of field tests, but could be included at

any stage.

The major concern with herbicide resistance

genes is that they might spread into related, weedy

species, most likely through sexual reproduction

(10). The potential drawbacks are obvious: Worldwide economic losses to weeds are still measured

in billions of dollars per year. While this is a greater

problem outside the United States, it is neither

a new problem nor one unique to genetically engineered plants. In many cases such existing problems are managed by rotating either crops or herbicides.

Researchers are also trying to insert pest resistance genes directly into plants, which could reduce the need for pesticides. Several companies

are pursuing such applications, but the principles

are exemplified by the efforts of Rohm & Haas.

Successful field tests have already taken place (see

ch. 3 and app. A) with tobacco plants engineered

to carry the delta-endotoxin gene from BT.

Different varieties of the toxin (derived from

different strains of B. thuringiensis) are poisonous to the larvae of some herbivorous insects, primarily certain Lepidoptera (moths and butterflies)

and Coleoptera (beetles). The toxin’s action depends on fundamental biochemical characteristics (pH, membrane permeability, etc.) of the larval digestive tract in these insects. As the larvae

mature, and their digestive tracts develop, they

become less sensitive to the toxin. Young larvae

are most sensitive.

The field test showed that the delta-endotoxin

gene is expressed in engineered tobacco plants.

The toxin produced in plant tissues conferred essentially complete protection against predation by

the tobacco hornworm Manduca sexta. This caterpillar is a common agricultural pest on a variety

of crops, and several companies are working on

protecting different crop species by this or a similar technique.

There appears to be little, if any, cause to be

alarmed at the direct consequences of this compound being present in large quantities in the environment. The BT toxin has been used in various

formulations since the first product was licensed

in 1962 (66). As indicated in chapter 4, it is presently available in 13 different formulations (e.g.,

powder or soluble concentrate) in over 410 different registered products. Total quantities that have

been administered are in the hundreds of thousands of tons, with ill effects on humans, vertebrates, or nontarget organisms virtually unknown. (For one of the rare citations of a human

problem associated with BT use, see (47).)

Yet there is still some reason for concern. Largescale applications of toxin+ obtaining plants or

novel microbial delivery vehicles might promote

the evolution of insect resistance to this currently

safe and effective agent by increasing the distribution and persistence of the toxin in the environment. Delta-endotoxin is extremely effective

against its target organisms. Evolutionary biologists would say it exerts a strong selection pressure. This means that given persistent exposure

to the toxin, particularly in sublethal concentrations, target organisms could be expected eventually to evolve tolerance or resistance to deltaendotoxin through natural selection.

Because the toxin is so unstable, and sporadically used, it generally does not persist long

enough for resistance to evolve. The BT toxin is

a biodegradable protein, sensitive to temperature,

moisture, and especially to ultraviolet (UV) light,

which causes its rapid decomposition. Biotechnology could change this by packaging the toxin in

new vehicles (e.g., the Mycogen product; see app.

A) placing it in new locations (e.g., inside host plant

tissues, as in the Rohm & Haas product) or both

(e.g., the Monsanto product) where it would be

protected from degradation. The toxin could persist in the environment long enough to allow natural selection to produce resistant insects. This

scenario is supported by at least one report of

evolved resistance to BT toxin (34), in which seeds

stored in silos are dusted with BT. In this setting,

where the toxin is protected from UV degradation, resistance in the insect pest has been observed to evolve rapidly, and in more than one

instance.

This problem is less one of product safety, however, than of useful product life. The declining

agricultural market for BT in recent years, as it
91

has been replaced by promising new compounds

like the synthetic pyrethroids, makes it unlikely

that loss of BT as an agricultural pesticide would

lead to an increased reliance on older, more dangerous chemical pesticides. But a consideration

of possible responses to a potential problem such

as this is illustrative.

Because the evolution of resistance is a product of selection pressure created by the chronic

presence of the toxin, either when or where it

is not needed (e.g., in roots or stems, in addition

to the leaves that are eaten), the problem might

be solved by limiting toxin distribution to the times

and places it is really needed. One way to do this

would be to limit the expression of the BT gene

to only the tissues subject to damage by herbivorous insects. The system could be refined further

by making gene expression inducible, so that toxin

production in the plant tissues is triggered by damage caused by herbivorous insects (27). This strategy would require the insertion of precisely controlled regulatory sequences along with the BT

toxin gene, an approach that is beyond the reach

of current techniques. But with increased understanding of the mechanisms of gene regulation,

it may be possible in the near future (21).

A second approach, while not so obvious, employs tactics that can be used effectively and immediately, though the logistics of this approach

may complicate existing methods of planting and

harvesting somewhat. It draws upon studies in

game theory of evolutionary stable strategies

(12,13,14,58). Some biologists who have studied

the relationships between pathogens or pests and

their hosts feel that pathogens or pests may adapt

more quickly to the defenses of agricultural crops

than to those of hosts in the natural environment

(1,32). The key seems to lie in the differences in

genetic variation in the two populations. Variation is higher in natural than in agricultural populations, because the latter often involve huge

areas of genetically homogeneous host plants. The

selection pressures in agricultural systems are

more often even and continual, in marked contrast to the spatial, temporal, and other variables

that complicate selection pressures in the natural environment. These even, continual selection

pressures are much easier to adapt to. Thus, anything that could be done to increase the genetic

variation (at least in the genes controlling pest

defenses) of the host population would likely lead

to a slower adaptive response in the pest.

Increasing genetic variation in agricultural populations could be accomplished by mixing genetically pest-resistant strains of crop plants with

strains not so protected. Modeling studies show

that as simple a change as planting a mixture of

50 percent resistant and 50 percent unprotected

seed in place of 100 percent resistant seed would

substantially extend the time it takes for the pest

to mount an adaptive response (32). The same principle also applies to other host/pathogen relationships, such as wheat/rust or corn/blight, or integrated pest management in general. Indeed, the

relationship could be extended to planting crops

that vary with respect to their tolerance to environmental factors (drought, cold) in areas where

wide annual fluctuations in these parameters occur. The net effect could well be an increase in

crop yields or productivity, although most often

there is a trade-off between yield and the degree

of resistance or tolerance. Just as complex communities seem best to resist the perturbing effects

of introduced species (17), so might genetically

complex agricultural systems better resist many

types of potential environmental challenge.

Other types of genetic modifications to plants,

such as altering photosynthetic pathways to increase efficiency and production rates, or modifying seed components to resist insect predation

and loss during storage, may well have environmental effects of an unforeseen nature. But much

larger changes in photosynthetic rates or biomass

productivity can be achieved more easily by planting different crops, something that takes place

constantly without review for potential environmental impacts. It hardly seems logical, therefore,

to review engineered plants for such an effect

when traditional agricultural crops are not subjected to such review.

Insect Communities

A great deal of research in genetically altered

plants and microbes focuses on ways to combat

insect pests—a major destroyer of both field and

stored crops. Relatively little work is presently being done with insects per se. Some plant modifi-
92

cations for controlling insects were discussed in

the preceding section. This section describes two

representative modifications to insect-targeted microbes: those intended to reduce crop losses to

the black cutworm, and modifications to viruses

that parasitize certain insect species.

Significant corn crop losses each year are attributable to one pest species—the black cutworm.

This lepidopteran larva feeds on the roots of corn

plants. To combat this pest, researchers are exploiting both its sensitivity to the delta-endotoxin

from B. thuringiensis and its narrow host range

of corn roots. Their work involves engineered versions of the common bacterium Pseudomonas

fluorescent.

Some strains of P. fluorescent live in the rhizosphere formed by the interaction between corn

roots and associated filamentous fungi. Scientists

at Monsanto have used a specific transposable element, Tn5, to insert the delta-endotoxin gene into

the chromosome of this bacterium. This transposable element is not common in nature (6,41). Monsanto scientists have disarmed it in two independent ways to make further movement after

insertion unlikely (41). In addition, frameshift mutations were inserted to further decrease the possibility of horizontal gene transfer due to reversion or complementation.

Greenhouse tests suggest that if corn seeds are

coated with the altered Pseudomonas, the bacterium will colonize the emerging roots upon germination. Preliminary results also indicate that

the engineered bacteria do not disperse significantly beyond the rhizosphere habitat in which

they are naturally found, nor do they seem to persist beyond the end of the corn growing season.

All these factors, coupled with the known, safe

record of the BT toxin, suggest that this environmental application is safe enough to be field tested

on a small scale. Such a test would measure survival, dispersal, and efficacy under realistic field

conditions, and could be expected to provide useful lessons for other microbial applications.

Another early microbial application aimed at insect pests uses the host specificity of a class of

viruses known as baculoviruses. These have relatively narrow host ranges, usually one or a few

closely related insect species. Different viruses are

specific for different pests, including the cabbage

looper (a moth larva) and the pine sawfly, both

of which threaten agriculture and forestry in the

United Kingdom.

During 1986, researchers at the Institute of

Virology in Oxford concluded a preliminary field

test of a cabbage-looper virus. To track the released virus, the researchers inserted specific,

marker DNA sequences into the engineered organism. Similar tests are planned for a virus specific

for the pine sawfly.

Scientists hope that learning more about the

genetics of host specificity in such viruses will enable them to target viruses precisely to specific

pests. But the difficulties of tracking a virus in

the environment, the possibilities for dispersal,

the ability of viruses to remain infective for long

periods, and the possibility of mutations disrupting

the host range of released forms must be considered before wholesale applications are undertaken. When asked about the degree of risk attending such work, one researcher responded,

My guess is no problem, but there are a variety of constructs possible, and some could have

broader effects than desired . . . One can consider many scenarios. In the worst case (also the

most improbable), the situation could not be corrected (36).

One of the least predictable effects of environmental alterations has been termed the “cascade

effect .“ Such effects are not likely to be common

consequences of planned introductions, and quite

unlikely to be associated with small-scale fieldtests.

But they are known to have been associated with

some large-scale environmental activities in the

past, so a brief description is in order. The term

‘(cascade effect” describes a community disruption in which a perturbation in numbers (or even

loss) of one species triggers reverberations

throughout the community, These effects could

alter predator/prey relationships or significantly

change community structure even if ecosystem

processes themselves are not altered.

Cascade effects can be both surprising and counterintuitive. One example can be found in the case

of a World Health Organization program to control

insect pests. The program used large-scale applications of DDT in Borneo to kill house flies. The
93

local lizard population, however, could not distinguish between flies that died of natural causes,

and were safe to eat, and those that succumbed

to the spraying program, and therefore were not.

Large numbers of geckos ate the flies and died,

as did cats that ate the poisoned geckos. The reduction in the cat population allowed rat numbers to rise, Stored food supplies suffered, and

the increased numbers of rats brought an increase

in the numbers of rat pest species. The result: an

outbreak of bubonic plague, a public health problem that would not normally be expected to result from a program of insect eradication (30.

Although such chains of events are almost

wholly irrelevant to considerations of field-test

safety, they should be kept in mind when the largescale applications that will follow are contemplated. It should also be noted that the negative

consequences of the house-fly eradication program resulted from an accumulation in the food

chain of an enduring, toxic compound. Widespread applications of genetically engineered

organisms are generally expected to reduce reliance on compounds of this sort. Also, most other

examples of cascade effects involve perturbations

of natural, not agricultural systems. Great care

must be taken in extrapolating from nature to the

artificial environments found in agriculture.

Nevertheless, large-scale applications of insecticides have sometimes increased the numbers of

insect pests when beneficial insects are eliminated

along with the pests (35).

Examples of cascade effects resulting from use

of a chemical pesticide bear little relation to the

problems most likely with planned introductions

of genetically engineered organisms. They do,

however, illustrate that complex relationships govern the interplay of organisms in ecosystems—

relationships that might not be comprehended

with cursory review, and that are not always immediately apparent.

Microbial Communities

Although some concern is raised over possible

consequences of introducing engineered animals

or plants, greater public apprehension is associated with possible uses of engineered microbes

(ch. 3). Planned applications include microbes

altered to prevent plant damage by herbivorous

insects (as just discussed), protect crops from frost

damage, increase nitrogen available to plants, and,

eventually, to degrade toxic wastes (covered later

in this chapter). These introductions may take

place either in limited agricultural settings or in

broadcast environmental applications.

The greater concern over planned microbial introductions has less to do with a higher probability of risk than with greater uncertainty about

some factors in microbial ecology and the requirements of monitoring or tracking that are peculiar to microbes. Extensive experience with past

microbial introductions does not suggest that potential problems are worse than those associated

with plants or animals. But few of the microbes

living in soils can be cultured in the lab, and little

is known about them or their relationships beyond the broad outlines of morphology and apparent function. Microbial ecologists do know, however, that there is a high degree of functional

redundancy among members of microbial communities, a redundancy that should act to mitigate any general consequences of perturbing a

particular microbial population, although some

limited communities (e.g., degraders of lignin) may

be less protected by such redundancy. Furthermore, a substantial literature suggests that microbial systems are resilient in the face of perturbations, and that it is often difficult to produce a

measurable impact, even by design, on such populations.

Developing environmental applications with microbes affords certain advantages over working

with plants or animals. Enormous populations

(numbering in the billions) can be studied over

hundreds of generations on a rapid time scale.

On the other hand, microbes present some unique

problems. They are microscopic, and the techniques for tracking their movements, distribution,

and numbers are often more involved, or more

tedious and expensive, than for plants or animals.

Microbes, particularly those in soil, can be difficult to detect. The most sensitive available techniques for sampling populations, based on detecting microbial DNA, are difficult or impossible to

apply if the DNA to be tested is taken from fewer

than a thousand cells, Smaller numbers—as low

as 100 cells per cubic centimeter—may be assayed
94

if bacterial colonies are cultured from naturally

occurring individuals and screened with techniques that rely upon resistance to specific antibiotics, or other biochemical markers. This assumes, however, that the species can be grown

in the laboratory.

Bacteria can persist in a microbial community

at levels undetectable by any existing sampling

technique. These levels can rise rapidly under

favorable conditions, so the inability to detect a

microbe does not mean that it is absent from an

environment. Microbial species are enormously

abundant—upwards of a thousand different species may be found per square yard of land surface (9). A single species may encompass from

5,000 to 20,000 genetically different strains or varieties, varying in their adaptive qualities and ecological requirements.

Microbes are also ubiquitous, found in every

terrestrial environment and habitat in which they

have been sought, including such hostile and unlikely sites as hot springs and subterranean

aquifers (11,20). Perhaps 90 percent of these species cannot presently be cultured in the laboratory, making them difficult to study. Despite such

obstacles, the ecological questions raised by the

environmental release of genetically engineered

microbes are not intractable, and a great deal of

relevant historical experience can be studied.

Genetic alterations to microbes for specific environmental purposes are many and various. This

section outlines two not covered elsewhere in this

report. The first—the application of “ice-minus”

bacteria to crop plants to protect against frost

damage–involves what was one of the more contentious of the early applications for permission

to field test, though for reasons other than the

scientific questions involved (see ch. 3). The second, involving the inoculation of crops with enhanced nitrogen-fixing bacteria, has been less controversial.

The technical details of the ice-minus application

are simple. Some bacteria contain, as a component of the cellular membrane, a protein encoded

by a single gene in the bacterial chromosome. This

protein can act as an efficient nucleus for the formation of ice crystals on the surfaces of plant

leaves or blossoms where the bacteria live. WithPhoto credit: Peter Forde, Advanced Genetic Sciences

Advanced Genetic Sciences Researcher Julianne

Lindemann spraying “ice-minus” bacteria on strawberry

plants in test plot on April 24, 1987. Protective clothing

was required by the California Department of Health

Services. Note reporters and onlookers in immediate

background where coffee and donuts were

consumed without hesitation.

out such nuclei, water does not generally freeze

at 32 “F. Rather, it supercools to between 5 and

100 below the “normal” freezing point before the

formation of ice crystals begins to take place.

Agricultural losses to frost damage each year

are variable but significant. Some estimates place

the average annual loss at $1.6 billion in the United

States, and $14 billion worldwide (15). Most of this

loss results from frosts that take place near harvest time, or near flower-budding time in spring.

Part of it might be avoidable if some protection

could be provided against snap frosts, as opposed

to hard freezes, because hard freezes are uncommon during the growing seasons of most crops.
95

a

protection could be afforded by deleting the “icenucleating” gene (or an essential part of it) from

the major bacterial strains living on the surfaces

of particular plants (potatoes and strawberries,

in the first fieldtests). These altered bacteria would

then be inoculated on the plant surfaces to be protected, in the hope that they would colonize them

and replace the naturally occurring bacteria (designated ice plus, or INA +, for ice nucleation

active).

Naturally occurring populations of ice-nucleating bacteria contain low numbers of individuals

that are ice-minus. The phenotype can be produced by any mutation that inactivates the production of the critical protein, and thousands of

such mutations are possible. Many could produce

ice-minus bacteria in natural populations. The primary genetic difference between these naturally

occurring ice-minus bacteria and those produced

with recombinant DNA techniques is that the latter are produced by a specific technique that yields

a consistent, precisely characterized, identifiable

genetic deletion, Such consistency and identity is

not a characteristic of the naturally occurring

strains. These and other factors led both the National Institutes of Health and the Environmental

Protection Agency to approve applications for preliminary, small-scale field tests of the bacteria,

which were successfully completed in 1987.

Some scientists suggested a worst-case scenario

that sounds like a cascade effect (42). According

to that scenario (which presupposed large-scale

applications, not small-scale field tests), large-scale

agricultural applications of ice-minus bacteria

might reduce the atmospheric reservoir of ice

nuclei. These atmospheric nuclei are critical for

precipitation, providing particles around which

ice crystals can form so that droplets can grow

large enough to fall as snow or rain. Dirt and dust

can act as sources of ice nuclei, but vegetable or

plant material is a better source (53,54). Another

major source for ice nuclei is marine phytoplank -

ton, living in the top layers of oceanic waters

(50,51). The sources of ice nuclei important to local precipitation are generally local (52,55), though

long-distance dispersion of bacteria is known to

be possible, if not common (19), and less likely

for good nucleators than nonnucleators.

Some scientists asked if reducing atmospheric

concentrations of ice nuclei could affect local rainfall, and perhaps even global weather, reducing

or redistributing patterns of precipitation. They

pointed to data suggesting that overgrazing in the

Sahel may have exacerbated drought conditions

in Sahelian Africa (43,49). Overgrazing reduces

plant biomass in an ecosystem, thus reducing the

suitable habitat for ice-nucleating bacteria, and

reducing the numbers of bacteria. Such a cascade

effect may have contributed to decreases in rainfall downwind of deforested areas.

Seeking to assess the likelihood of this scenario,

OTA commissioned two analytical studies by

groups taking slightly different approaches to the

problem (4,60). Both groups made assumptions

to produce a worst case scenario. Both concluded

it is unrealistic to expect any significant negative

impact on global climatological patterns from

large-scale agricultural applications of ice-minus

bacteria. The likelihood of local changes in precipitation patterns or densities is perhaps slightly

higher, they concluded, but still extremely low.

Indeed, to put the question in the appropriate

context, the potential for negative environmental

consequences from large-scale applications of ice

minus bacteria should be compared with the po-
96

tential for such consequences from other strategies for reducing or eliminating INA + bacteria

in agriculture, such as the use of chemical bactericide. Several significant uncertainties in these

analyses could be resolved, however, by further

research and experimental studies.

In another planned introduction of engineered

microbes, rhizobial bacteria are being studied in

an effort to increase nitrogen fixation in soil, and

thus to decrease reliance on costly fertilizers. Scientists at BioTechnica International (Cambridge,

MA) have engineered a strain of Rhizobium

meliloti, symbiotic on alfalfa roots, to increase its

production of nitrogen. This has been accomplished by increasing the number of promoter sequences that regulate the activity of genes involved

in nitrogen fixation metabolism, Greenhouse tests

suggest possible increases of available nitrogen

as high as 17 percent, and though field tests were

originally planned for 1987, they were later postponed until 1988. A long history of agricultural

inoculations with different varieties of nitrogenfixing bacteria suggests that far-reaching or negative environmental consequences are quite unlikely, though this question is explored in more

detail later in this chapter.

Some individuals believe other approaches to

nitrogen fixation may lead even more quickly to

practical improvements. This feeling stems partly

from the fact that nitrogen fixation is an energyintensive process. Sufficient energy may not be

available under most conditions to sustain appreciable increases in nitrogen fixation by microorganisms residing on or around root surfaces.

It is also true that bacteria that are good modulators or colonizers of roots also tend not to be the

most efficient fixers of nitrogen, though there is

tremendous variation among naturally existing

strains.

Improving the energy efficiency of these bacteria is, of course, one object of research. But re1

I

i

I

I

i
97

search efforts might profitably be invested in improving the ability of nitrogen-fixing microbes to

withstand the stresses encountered in their

rhizobial environments and in the processes of

storage and agricultural inoculation, Most bacteria now marketed as inoculants fare poorly under these conditions, especially in the tropics, with

the result that most attempted inoculations deliver only a small fraction of the intended microbes

to the application site. Research in these areas

might dramatically improve the success of inoculation techniques while effectively exploiting the

existing reservoir of variation among naturally

occurring rhizobial bacteria in different environments (2,3).

Aquatic Communities

Work on altering aquatic community species is

being pursued in a number of areas. Potentially

fruitful lines of investigation involve fisheries biology and aquiculture. At least two different research groups are exploring methods to enhance

the production of “trophy” salmon in the Great

Lakes region and the Pacific Northwest (see app.

A). Under a flexible definition of biotechnology,

this research may qualify for consideration in this

report, or it may not be considered to differ significantly from past fisheries practice.

The technique used to try to produce the trophy salmon is called “heat shock.” During an early,

sensitive stage of embryonic development, salmon

eggs are briefly subjected to unusually high temperatures (38 degrees Celsius): temperatures high

enough to disrupt some metabolic processes, but

not so high as to kill the developing fish embryo.

This environmental insult disrupts normal cell division, causing a spontaneous doubling of the chromosomal number in each cell of the developing

embryo.

Chromosomal doubling triggers a series of physiological effects, starting with a disruption of the

hormonal system. The fish fail to mature sexually and remain sterile throughout their lives. This

frees them from the normal cycle of growth, maturation, sexual reproduction (spawning), and death

that usually limits their lifespan. Because these

fish fail to spawn and die, they are expected to

continue to live and grow, eventually reaching record sizes.

Salmonid fish are among the top predators in

whatever community they inhabit. So initially it

may appear that the planned introduction of these

fish would violate a cardinal principle mentioned

earlier: Do not introduce polyphagous species, particularly if they occupy a high position in a food

chain (45). But these fisheries are already managed by humans. Even under generous assumptions about the survival of released fingerlings,

the resulting adults are unlikely to number more

than several hundred among stocked populations

that number in the millions (33). Furthermore, the

same property that causes these fish to reach such

large sizes prevents them from reproducing. It

is impossible that any environment will ever contain these fish except through planned stocking.

Careful monitoring of the fish’s release and growth

rates should help to avoid or correct serious unanticipated effects.

Other work with aquatic communities focuses

on marine algae, to enhance the rates at which

they produce substances useful in food preparation, such as carrageenan or agar (see app. A).

Some aquatic algae have also been considered as

potential agents to extract toxic compounds or

heavy metals from aqueous solution (59). It might

even be possible to exploit algae for mining or

mineral recovery operations. But most of these

applications involve aquatic plants that function

in their environments as primary producers. Genetic alterations to improve or adjust their rates

of activity could well affect other members of

aquatic communities. Such possible effects are discussed in the following section.

POTENTIAL IMPACTS ON ECOSYSTEM PROCESSES

Ecosystems are enormously complex, and to within the numerous populations of any given spereach a clear understanding of how they func- cies, and between the great numbers of different

tion is commensurately difficult. Their complex- species that form any biological community. It is

ity stems from the many and diverse interactions also due to the links between the physiological
98

processes of organisms and the geological processes by which minerals are derived, distributed,

and moved in the physical world. For example,

the availability of minerals liberated from rocks

is affected by living things (especially plants or

microbes) as they influence rates of erosion.

As a way of reducing this daunting complexity

to manageable proportions, some ecologists devote more study to the distribution and movement

of a small number of vital elements and minerals

than to the activities and attributes of living creatures. The most important of these vital elements

are carbon, nitrogen, phosphorous, and sulfur.

These elements are “rate-limiting.” In other words,

the amount of these elements in biologically accessible forms determines the total tissue of living

organisms (biomass) that can be assembled in the

ecosystem. (Phosphorous and sulfur are covered

in detail in 9,22.) Carbon and nitrogen are discussed in this section.

Ecosystem processes are the vehicles by which

these rate-limiting elements and their different

molecular forms move, or cycle in ecosystems.

The two major ecosystem processes are nutrient cycles and energy flow. These processes can

be, and sometimes are, considered separately. This

report will consider them together, and deal with

them primarily in the language of mineral or nutrient cycles.

Every time an element is altered from one

molecular form to another, or exchanged between

different organisms, some chemical bonds are broken and others formed. Each of these actions either consumes or liberates energy. The integration of countless individual events of this sort is

the immediate mechanism by which nutrients cycle and energy flows through an ecosystem.

The major factors driving ecosystem processes

are the production of energy and the conversion

of carbon into biological forms by photosynthesis, or carbon fixation. Where carbon is ratelimiting, it places an absolute upper limit on the

biomass a system can support. Under such circumstances, competition for carbon is intense, as

for example among soil microbes. Plants produce

most of the biologically accessible forms of carbon.

Decomposers-organisms that degrade plant

material—play the major role in moving carbon

from one reservoir into another (e.g., from one

plant, through decay, into another). Most decomposes are invertebrates (insects, nematodes, and

so on) or microbes (bacteria and fungi), living primarily near the soil surface in what is termed the

“litter layer” of detritus that accumulates from

above, or just below, in the topsoil. Larger herbivores, or vertebrates, play a smaller role, usually

assisted by an intestinal flora of symbiotic microbes.

Physical parameters, such as climate, soil quality, and available moisture, affect the distribution

of both plants and decomposes. As a result, a

range of ecosystems—different communities of

plants and decomposes, associated with particular ecological qualities–has evolved. Table 5-3 illustrates several different terrestrial ecosystems

and presents data indicating the patterns of carbon storage and movement in them.

Nitrogen is the nutrient most often cited as ratelimiting in terrestrial ecosystems. Although one

form of nitrogen makes up nearly 80 percent of

Table 5-3.—Production and Decomposition in Six Ecosystem Types

Mean Mean Litter

NPP biomass Litterfall accumulation Decomposition

tons/ha/yr tons/ha tons/ha/yr tons/ha k/yr

Tundra 1.5 10 1.5 44 0.03

Boreal forest . . . . . . . . . . . . . . . . . . . . . . . 7.5 200 7.5 35 0.21

Deciduous forest . . . . . . . . . . . . . . . . . . . 11.5 350 11.5 15 0.77

Grassland . . . . . . . . . . . . . . . . . . . . . . . . . . 7.5 18 7.5 5 1.50

Savannah . . . . . . . . . . . . . . . . . . . . . . . . . . 9.5 45 9.5 3 3.20

Tropical forest . . . . . . . . . . . . . . . . . . . . . . 30.0 30.0 5 6.00

Abbrevlattons: NPP -= net primary productivity, the total amount of living material produced by the organisms in an ecosystem; ha -hectare; yr = year; k = fractional

weight loss of litter material (a value of 1 means the rates of production and decomposition are equal).

SOURCE: J.R. Gosz, C.N. Dahm, and P.W. Flanagan, “Ecological Impact of Genetically Engineered Organisms on Ecosystems,” contract report prepared for the Office

of Technology Assessment, U.S. Congress, 19S7.
99

the atmosphere, biologically accessible forms are

more limited.

The nitrogen cycle—illustrated in figure 5-l—

is the most complex major nutrient cycle because

the element can exist in so many qualitatively

different molecular forms, Abiotic factors and the

actions of living things influence the production

and persistence of these forms.

While plants can absorb gaseous nitrogen or nitrogen dissolved in water through their roots, microbes provide the major pathway for nitrogen

incorporation into living material. Specifically,

rhizobial bacteria are responsible for nitrogen fixation in agriculture. These microbes live in very

close association with the roots of certain plants

(legumes), often in small granules or nodules attached to the roots. In essence, they deliver fixed

nitrogen directly to the host plant. The biochemical pathway resulting in nitrogen fixation is large,

complex, and energetically expensive to operate,

involving at least 17 different structural genes,

with associated regulatory sequences. This genetic

package exists in similar form in all rhizobial bacteria, an evolutionary conservation suggesting that

the pathway is quite important to the bacteria.

Scientists trying to enhance nitrogen fixation face

the formidable task of improving the performance

of a genetic sequence that has been refined by

natural selection for billions of years. Nevertheless, researchers are making the attempt, even

trying to transfer the complex of nitrogen fixaFigure 5-1 .—The Nitrogen Cycle

k

\

immobilization

sedimentation

inorganic)

m

The nitrogen cycle: processes in terrestrial and aquatic systems. The microbially mediated processes include mineralization,

vitrification, denitrification, immobilization, and N-fixation.

SOURCE: Office of Technology Assessment, 1988.
100

tion genes into plants to enable them to produce

their own nitrogen without relying on associated

bacteria.

If the nitrogen-fixing abilities of rhizobial bacteria were enhanced in such a way as to make

the resultant increase in available nitrogen general throughout the host environment, rather than

restricted to the host plant per se, a variety of

environmental consequences might result. The potential consequences of such a successful application are listed here (22), in order of decreasing

probability.

I. a) Increased leaf and shoot production in

target plants

b) Decreased root growth and biomass

c) Increased decomposition rates in some

systems

d) Increased ammonification and vitrification in soil

e) Increased competition on nonnitrogenfixing plants and alteration of plant community structure, with reverberations

throughout the associated ecological community

2. a) Decreased decomposition rates in some

systems

b) Increased potential for other element

limitations, especially if 2a results

c) Altered chemical exchange capacities and

pH shifts

3. a) Decreased mycorrhizal associations (dependent on 2b)

b) Shift from carbon-based plant defense to

nitrogen-based defense (or from immobile

to mobile defense compounds)

c) Altered foliage tissue palatability and herbivory (dependent on 3b)

d) Increased terrestrial denitrification rates

and increased emissions of Nitrogen gases

(dependent on 1d and 2c)

4. a) Increased leaching loss of nitrate

b) Increased eutrophication of drainage

water

c) Increased algal production in receiving

waters

d) Increased carbon enrichment of aquatic

sediments

e) Increased anaerobic conditions in aquatic

habitats

f) Increased aquatic vitrification and

denitrification rates and gaseous emissions to the atmosphere.

Some data suggest such consequences are not

purely hypothetical, that under very special conditions they might actually be likely (63). Generally, however, such a concatenation of consequences rests on a series of assumptions. For most

of them to occur, the introduced rhizobia would

have to move beyond agricultural lands. They

would then have to successfully nodulate, or colonize, wild plants, and provide substantially more

nitrogen to those wild plants than is already provided by native rhizobia, This also requires that

the host specificity of the introduced rhizobia

would have to change genetically so they could

infect the wild plants, and the introduced bacteria would have to be successful in modulating the

native plants in competition with native bacteria.

As cited above, considerable literature and experience demonstrates the remote likelihood of each

of these assumptions; to achieve all of them at

once, the probability is exponentially less likely.

Indeed, a review of these assumptions and potential events leads many experts on nitrogen fixation to believe it would be difficult to conceive

of a planned introduction less likely to have negative consequences than introducing engineered

varieties of nitrogen-fixing bacteria.

Ecosystem processes reflect the sum total of the

actions of all living things in the system. Individuals concerned about planned introductions of

genetically engineered organisms fear applications

that might affect such fundamental processes as

nitrogen or phosphorous cycles. And although

basic changes to an ecosystem process would be

difficult to accomplish, it might be easier to affect changes in rates of flow of some components

through a portion of the process. By the time such

effects were noticed, however, a community might

already have been substantially altered. According to two researchers in this field,

. . . the quality of an environment can change

markedly with no significant change in gross

measures of the rates of processes. Fish production in two lakes may be the same (as lbs./year)

when one produces mostly rainbow trout and the

other mostly carp, but no human would say that

the two lakes are therefore indistinguishable with

regard to fish (9).
101

Attempts to detect such changes in ecosystems

have led to the study of so-called indicator species, species more sensitive than other organisms

to environmental changes (40).

The use of indicator species requires the identification of species that are particularly sensitive

to the environmental parameter of interest—for

example, the presence of toxic compounds or the

abundance of specific nutrients. Indicator species

can give early warning of an impending change,

allowing preemptive measures to be taken. Without such early warnings and preemptive action,

the task of restoring a disrupted ecosystem is difficult, expensive, and slow, if even possible (38).

A better understanding of community relationships should make indicator species increasingly

useful, especially in risk assessment and management. Nevertheless, any planned introduction that

is likely to alter a fundamental ecosystem process should undergo careful scrutiny. None are

planned in the foreseeable future.

Possibly of eventual concern, however, are applications intended to correct existing serious, generally recognized environmental problems, such

as the presence of toxic chemicals. Naturally occurring microbes exist that can degrade many different, complex, toxic compounds—herbicides and

pesticides, industrial solvents, wood preservatives,

plasticizers, dyes, etc. (22,26). Biotechnology researchers are trying to enhance these natural

degradative abilities in some microbes and introduce them into others. Success in such efforts

could help significantly in decreasing the toxic

waste problem that promises to be so difficult and

expensive to resolve (61).

Cascade effects might be triggered by the structural similarities between naturally occurring

plant materials and some of the complex organic

compounds found among toxic wastes. If degraders were engineered and introduced without sufficient constraints upon their specificity, they could

function as ecological generalists, breaking one

of the foremost rules for introducing organisms

into new environments. Communities of decomposers may also be more vulnerable to perturbations than most microbial communities, because

the decomposition of lignin and cellulose (the

structural components that make up from 50 to

90 percent of the biomass of higher plants) is carried out by a relatively narrow range of microorganisms. A disruption of the population dynamics of one species of decompose, in a limited

community of decomposes made up of only a

small number of species, could conceivably have

a significant impact on the community.

In contrast, many other microbially mediated

processes are carried out by the members of much

larger, more diverse, and therefore more buffered, microbial communities. Indeed, no existing evidence indicates that populations even of

microbial degraders are subject to cascade effects

following perturbation. Such scenarios are purely

speculative. In fact, some researchers in this area

feel the introduction of engineered microbes to

help in the degradation of organic pollutants is

sufficiently distant that it need play no role in current deliberations over the safety of planned introductions, although similar introductions of

naturally occurring organisms are not at all uncommon.

Finally, it is important to keep the possible consequences of planned introductions of genetically

engineered organisms in perspective. As one

group of ecologists has concluded, “Our analyses

and remarks to this point may give the impression that we are against the release of any genetically altered organisms into the environment, This

is not our view. In fact, we are enthusiastic about

the prospects offered by biotechnological solutions

to environmental problems ranging from increased productivity of agricultural systems, to

the control of pests and pathogens, and the

removal of many chemical toxins from the earth’s

soils and waters. We further expect that many,

if not most, environmental applications of biotechnology can be made into safe and productive ventures” (28). Risk assessment and management,

discussed in chapter 6, are crucial to that undertaking.
102

SUMMARY AND CONCLUSIONS

The major concern of some scientists over the

planned introduction of genetically engineered

organisms stems from the potential for unexpected or unforeseen consequences; other scientists believe that the likelihood of such consequences is no different, or even lower, for

engineered organisms than for varieties or cultivars produced by widely accepted methods. A variety of disruptions to local populations or to more

general ecosystem processes could result, but do

not seem likely to result from any of the planned

introductions now contemplated. Experiences

with past introductions of organisms into new

environments provide some limited clues to the

nature of those disruptions, but a much better

analogy for planned introductions of engineered

organisms likely in the near future is that with

new crops or cultivars in agriculture.

Only a small fraction of introduced organisms

have become pests or have significantly affected

their new environments. These species-called

colonizing species, or weeds-differ significantly

in their adaptive capabilities from most genetically

engineered organisms intended for planned introductions. For the near future, engineered

organisms generally will differ from nonproblematic parental strains by only one or a few structural genes. There are, however, several examples of single gene changes affecting the virulence

or host range of a parasite or pathogen. Although

engineered organisms are no more likely than

nonengineered ones to be susceptible to such

changes, until sufficient experience is gathered

caution is indicated.

Environmental disruptions stemming from the

deliberate release of engineered organisms might

take place at any level—from the local population

to ecosystem processes of energy flow or nutrient cycles. Plant introductions seem least likely

CHAPTER 5

1. Alexander, M., “Ecological Consequences: Reducing the Uncertainties, “Issues in Science and Technology 1(3):57-68, 1985.

2. Alexander, M.A., “Ecological Constraints on Nitrogen Fixation in Agricultural Ecosystems, ’’Advances

in Microbial Ecology 8:163-183, 1985.

to result in problems because of the low mobility

of plants and restricted horizontal gene flow between them. Animal communities, because of the

greater mobility and higher propensity for gene

transfer, seem slightly more vulnerable to disruption, though the probability still seems quite low.

Furthermore, most anticipated animal applications

involve livestock, suggesting that the potential for

disruptions of natural communities is not great.

Most difficult to assess are applications involving microbes. Microbial mobility is low but dispersibility is relatively high, as is the potential for

gene transfer. Much remains to be learned about

the composition and relationships among naturally occurring microbial communities (of which

only a small portion of the members can be cultured in laboratories) before general methods of

risk assessment will be available (see ch. 6). But

a substantial body of experience suggests that

microbial introductions are not likely to produce

problems.

The least likely, but potentially most serious ecological impacts involve the disruption of ecosystem processes, such as energy flow and nutrient

cycling. Such disruptions could be difficult to reverse and far-reaching in their effects. They could

result as a consequence of engineering microbes

to increase their capabilities as degraders, e.g.,

to enhance the decomposition of woody tissues

containing lignin or cellulose, or to help in the

cleanup of toxic organic wastes. In the latter case,

however, effective control might well be exerted

by managing the available supplies of carbon,

which are likely to constrain degradation rates.

The potential problems associated with such enhanced degraders must be weighed against the

existing, serious problems associated with toxic

wastes and the chemical technologies that are their

source.

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24. Hirano, S. and Upper, C. D., “Ecology and Epidemiology of Foliar Bacterial Plant Pathogens, ” Annual

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25. Howarth, F. G., “Classical Biocontrol: Panacea or

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“Induced Resistance and Interspecific Competition

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28. Lenski, R.E., and Istock, C. A., “Are There Specific

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29. Levin, S. A., and Harwell, M. A., “Potential Ecological Consequences of Genetically Engineered Organism, ” Environmental Management 10(4):495-513,

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32. Massey, A., and Gould, F., “The Genetic Basis of

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33. Mathews, B. E., “50-Pound Kings for Michigan?”

Michigan Outaf-Doors, May 1986.

34. McGaughey, W. H., “Insect Resistance to the Biological Insecticide Bacillus Thurin@”ensis,” Science

229:193-195, 1985.
104

35. McNaughton, S.J., and Wolf, L. L., General Ecolo~

(New York, NY: Holt, Rinehart & Winston, Inc.,

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36. Miller, L. K., University of Georgia, personal communication, 1985.

37. Mooney, H. A., and Drake, J.A. (eds.), Ecology of

Biolo@”cal Invasions of North America and Ha waii,

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38. Moss, B., “The Art of Lake Restoration, ” IVew Scientist 113(1550):41-43, 1987.

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Environment: Key Issues (Washington, DC: National Academy of Sciences Press, 1986).

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DC: National Academy of Sciences Press, 1986) and

National Research Council, Pesticide Resistance:

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41. Obukowicz, M. G., Perlak, F.J., Kusano-Kretzmer,

K., et al., “IS50L As A Non-Self Transposable Vector Used to Integrate the Bacillus thuringiensis

Delta-Endotoxin Gene Into the Chromosome of

Root-Colonizing Pseudomonads,” Gene 51:91-96,

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42. Odum, E. P., “Biotechnology and the Biosphere, ’’Science 229:1338, 1985.

43. Parton, W .J., and Schnell, R. C., “Use of an Ecosystem Model to Study Potential Interactions Between

the Atmosphere and the Biosphere,” Proceedings,

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San Francisco, 1975.

44. Pimentel, D., Gleniston, C., Fast, S., et al., “Environmental Risks of Biological Pest Controls, Oikos

42:283-290, 1984.

45. Pimm, S. L., and Levin, B. R., “Impact on Competitive Abilities of Specific Genetic Alterations)” Ecological Issues Relevant to Environmental Application of Genetically En@”neered Orgazu”sms, E. Norse

(cd.), contract report prepared for the Office of

Technology Assessment, U.S. Congress, 1986.

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]ogi”ca] Society of America Bulletin 24(1):3-11, 1978.

47. Samples, J. R., and Buettner, H., “Corneal Ulcer

Caused by a Biologic Insecticide Bacillus Thurin-

@“ensis,” American Journal of ophthalmology

95(2):258-260, 1983.

48. Schippers, B., and Gains, W., Soil-Borne Plant Pathogens (New York, NY: Academic Press, 1979).

49. Schnell, R. C., “Biogenic Ice Nucleus Removal by

Overgrazing: A Factor in the Sahelian Drought?”

Final Report to the Rockefeller Foundation, New

York, 1975.

50. Schnell, R. C., “Ice Nuclei Produced by Laboratory

Cultured Marine Phytoplankton,” Geophysical Research Letters 2(11):500-502, 1975.

51. Schnell, R. C., “Ice Nuclei in Seawater, Fog Water,

and Marine Air Off the Coast of Nova Scotia: Summer 1975, ” Journal of the Atmospheric Sciences

34(8):1299-1305, 1977.

52. Schnell, R. C., “A New Technique for Measuring

Atmospheric Ice Nuclei Active at Temperatures

from – 20“C to O“C, With Result s,” Seventh Conference on Inadvertent and Planned Weather Modification, Banff, Alberta, Oct. 9-12, 1978 (Boston,

MA: American Meteorological Society, 1979).

53. Schnell, R.C., and Vali, G., “Biogenic Ice Nuclei, Part

I: Terrestrial and Marine Sources)” Journal of the

Atmospheric Sciences 33:1554-1564, 1976.

54. Schnell, R. C., Delaney, A. C., and Gillette, D. A., “Ice

Nuclei Measurements During Wind Erosion Episodes, ” Proceedings, IX ATucleation Conferences,

Galway, Ireland, 1977.

55. Schnell, R. C., Wrobell, B., and Miller, S. W., “Seasonal Changes and Terrestrial Sources of Atmospheric Ice Nuclei at Boulder, Colorado,” IAMAPICCP VII Conference on Cloud PhLvsics, Clermont -

Ferrand, France, 1980.

56. Sharples, F. E,, “Relevance of Lessons From Introductions of Exotic Species,” Ecological Issues Relevant to Environmental Application of Genetical[V

En&”neered Organisms, E. Norse (cd.), contract report prepared for the Office of Technology Assessment, U.S. Congress, 1986.

57. Simberloff, D., “Predicting Ecological Effects of

Novel Entities: Evidence From Higher Organisms, ”

Biotic Crises in Ecological and Evolutionary Time,

M.H. Nitecki (cd. ) (New York, NY: Academic Press,

1981).

58. Smith, J. M., The Evolution of Sex (Cambridge: Cambridge University Press, 1978).

59. Sutton, C., “Desmids, the Algae With a Taste for

Heavy Metal,” New Scientist 113:45, 1987.

60. Upper, C, D., Hirano, S. S., and Vali, G., “An Assessment of the Impact of Large-Scale Applications of

Ice-Minus Bacteria and Other Procedures Designed

to Decrease Population Sizes of Ice-NucleationActive Bacteria on Crops,” contract report prepared

for the Office of Technology Assessment, U.S. Congress, 1986.

61. U.S. Congress, Office of Technology Assessment,

Superfund Strategy, OTA-ITE-252 (Washington,

DC: U.S. Government Printing Office, April 1985).

62. Vidaver, A. K., “Biological Control of Plant Pathogens with Prokaryotes,” Ph-~opathogenic ProkaEvotes vol. 2, M.S. Mount and G.E. Lacy (eds. ) (New

York, NY: Academic Press, 1983).

63. Vitousek, P. M., Walker, L. R., Whiteaker, L. D.,
Mueller-Dombois, D., and Matson, P. A., “Biological Invasion by Mtiyrica fa.va Alters Ecosystem Development in Hawaii, ” Science 238:802-804, 1987.

64. Weller, D. M., ‘(Application of Fluorescent Pseudomonades to Control Root Diseases,” Ecologv and

Management of Soilborne Plant Pathogens, C.A.

Parker, A.D. Rovira, K.J. More, et al. (eds.) (St. Paul,

MN: American Phytopathological Society, 19851.

65. White, G., Plant Introduction Officer, Agricultural

105

Research Service, U.S. Department of Agriculture,

personal communications, December 1986 through

February 1987.

66. White, J., National Pesticide Information Retrieval

Service, Purdue University, personal communication, Apr. 16, 1987.

67. Windels, C. E., and Lindow, S. E., Biological Control

on the PhyZloplane (St. Paul, MN: American Phytopathological Society, 1985).

Page

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Table Page

6-1. Types of U.S. Environmental protection Agency Biotechnology Risk

Assessment Projects ● *****.**,** . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .118
Chapter 6

Risk Assessment

During the 1970s, public concern about the effects of technology on the environment and human health heightened. As mounting scientific evidence confirmed that many chemical substances

produced adverse effects (both acute and chronic)

on humans and the environment, the government

established programs to control potential hazards.

protocols and procedures—methods for the assessment of risks—were developed to enable regulators to evaluate potential hazardous substances.

(See ch. 3 for discussion of the regulatory regime

and public perceptions of these issues. )

Risk assessment of recombinant DNA technology is not new, nor-is risk assessment of biological products. Nevertheless, questions concerning

risk assessment of planned introductions of geneticall y engineered organisms into the environment recently have become the subject of debate.

Some scientists perceive some risks associated

with intentionally introducing these organisms as

unique. Others believe introducing recombinant

organisms is no different (and probably safer, because scientists constructed them with precision)

than introducing nonrecombinant organisms,

which has occurred for millennia.

Are there unique risks in environmental applications of genetically engineered products? Is additional information needed to assess the risks accurately? Can existing assessment methods (e.g.,

for other biological risks, or for chemical risks)

be applied to the planned introductions of genetically engineered organisms? Are there areas

where available baseline data are sufficient?

RISK ASSESSMENT V. RISK

Risk assessment is the use of scientific data

to estimate the effects of exposure to hazardous materials or conditions. Derived from a factual base, risk assessment identifies and characterizes the magnitude of potential adverse affects

—either their quality or quantity. It is a separate

and distinct process from risk management.

Risk management is the process of weighing alternatives to select the most appropriate regulatory strategy or action. It integrates

the results of risk assessment with technical, social, economic, and political concerns. Carried out

by regulatory agencies under legislative mandates,

risk management is a decisionmaking process requiring value judgments that compare potential

risks and benefits, and determine the reasonableness of control costs. Benefits are part of the calculus of risk management. For example, risk

management of biotechnological products involves

comparing their benefits and problems against

those associated with products they are designed

to replace.

Risk

MANAGEMENT

management must also consider the

economic and social costs of regulation. These

include the burden of paperwork associated with

regulation, and the costs of mitigation and control technologies that channel resources away

from production per se (33). The process of risk

management depends upon the scientific findings

of risk assessment, as well as on public opinion.

Chapter 3 describes the significant impact of public opinion, in particular local communities, on

environmental applications of biotechnology. A

separate OTA report surveyed public perceptions

of biotechnology (48).

While recognizing that complex interrelationships between risk assessment and risk management exist, a key to improving the current process is to distinguish between those aspects of the

process that are more or less scientific (risk assessment) and those that are matters of policy or value

judgments (risk management). In fact, a 1983 report by the National Academy of Sciences recommended that regulatory agencies establish and

109
110

maintain clear conceptual distinction between the

two processes (33).

The domains of risk assessment and risk management of environmental applications of genetically engineered organisms are often blurred in

debates on this controversy. This chapter focuses on risk assessment and, more specifically, on the first step in the process of risk

assessment: “risk identification.” To a lesser

extent, issues of risk management are considered when those issues derive from the scientific underpinnings of risk assessment. The

role of the Federal Government in managing the

risks associated with the environmental release

of genetically engineered organisms, an issue presently being analyzed by the General Accounting

Office (15), is beyond the scope of this report. This

chapter also does not assess the various domains

of risk management-e.g., the economic and social

benefits that could be derived from planned introductions of genetically engineered organisms.

METHODS TO ASSESS RISKS OF PLANNED INTRODUCTIONS

An orderly process for organizing and interpreting information about the potential health or environmental risks of planned introductions of genetically engineered organisms must be developed

and refined. To date, the methods and models proposed for risk assessment of biotechnology have

been derived principally from those developed for

chemicals released into the environment (13,14,

16,17,45).

Some aspects of chemical and physical risk

assessment lend themselves well to evaluating

risks associated with living organisms, particularly

containment and mitigation (17). Other aspects of

the models do not apply well to living organisms,

which reproduce and are subject to selection pressure, or die out (45). Generally the risk assessment

process for planned introductions involves:

●

●

●

●

risk identification—identifies the potential

risk, designating its source, mechanism of action, and potential adverse consequences;

risk-source characterization-characterizes the potential sources of risk, describing

types, amounts, timing, and probabilities of

harmful events;

exposure assessment-considers exposure

risks, estimating intensity, frequency, and duration of exposure to the risk agent;

dose-response assessment–analyzes the

relationship between amount of exposure and

extent of effects; and

● risk estimation—estimates, within a range

of uncertainty, the overall risk (14,47).

At present, standardized protocols do not exist

for predicting either the kinds of risks or the magnitudes that could be associated with planned introductions of genetically engineered organisms

into the environment. Chemical fate models, epidemiological models, and effects models to assess

aspects of environmental applications are useful,

but not complete. Nevertheless, risk assessment

is not an impossible task and conducting a flexible, case by-case, science-based risk assessment (19,36,40) develops and enhances the risk

assessment structure Small-scale, experimental field testing will enhance significantly both

the basic scientific database and the ability to

modify existing risk assessment models Some

argue, however, that developing an adequate

assessment structure requires substantial new resources beyond those currently obligated for testing and evaluating chemical and other inert hazardous substances (16). In either case, risk

assessment raises questions and illustrates data

requirements that must be addressed. The implications that many of these questions have for a

national research agenda are discussed at the end

of this chapter.
111

CONSIDERATIONS TO EVALUATE IN ASSESSING

POTENTIAL

Identifying and evaluating the array of elements

to consider for risk assessment of environmental

applications of genetically engineered organisms

is one of the issues that must be addressed. Yet

underlying this evaluation is the fundamental

question of whether or not the entity should be

regulated strictly as a product, or as a product

that is special because it derives from recombinant DNA processes. Historical considerations of

risk assessment and regulation indicate that

process-based decisions are not logically consistent with assessments of other biological products.

But are there other important criteria that

should be analyzed? Some argue that there are,

and one of the first attempts to predict or classify

potential environmental impacts of the introduction of genetically engineered organisms described

five parameters (l):

Possible Negative Effects.–Before establishing

complex risk assessment schemes to address potential problems, this basic question should be examined. If there are none, then no cause for concern exists.

Survival.—Will the engineered organisms survive when introduced? If not, then there is little

likelihood that an ecological problem might arise.

If, however, the organism intended for release has

been designed to fit a certain role and to survive

in the environment, then further assessment is

required.

RISKS

Reproduction. -Many intended applications do

not merely require survival or persistence, but

depend on replacement or multiplication of the

organism to achieve the desired endpoint. Reproduction of an organism leading to an overwhelming net increase in number could increase the

probability of unintended potential effects.

Horizontal Gene Transfer (see ch. 4).–

Horizontal transfer of genetic material could be

a concern even if the released engineered organisms die after performing their intended function.

Transportation or Dissemination.—If the

organisms move beyond the environment in

which they were released and were intended to

function, they become a potential agent for interacting with other populations or communities.

This could have unintended and unpredicted consequences.

Many standards—both positive and negative—

exist to gauge the value of each of these criteria,

and in particular the first question. Yet, in assessing risks, uncertainties will always exist because

the ability to ask questions or pose problems exceeds the ability to answer them. The risk management process must be designed to assess the

value of these and other criteria and, as indicated

earlier, to weigh the benefits and risks of new

products against those of old ones. Nevertheless,

scientific criteria important to risk assessment

(especially risk identification) of planned introductions applications can be identified, and are discussed in the rest of this chapter.

WHAT RISK ASSESSMENTS AND REVIEWS ARE NECESSARY?

Basic to all arguments about the risks of deliberate release of any non-native plant or animal

are risk management decisions about the kinds

of hazards that are tolerable or intolerable. It is

clear that some planned introductions warrant

greater concern than others (32). An application

with some degree of risk, but with the potential

for widespread benefit, would probably be subject to detailed regulatory review. Regulatory review should also, however, be flexible, Thus, for

effective and efficient regulatory review, certain

applications of genetically engineered organisms

could be identified as having negligible risk (e.g.,

see Coordinated Framework for Regulation of Biotechnology, 51 F.R. 22302). Such applications could

be processed through an abbreviated review or

be exempt from review.

Can categories be identified for which abbreviated review or exemption is appropriate? For

example, case-by-case reviews at appropriate levels of scrutiny of planned introductions for cur-
112

rently accepted agricultural practices that differ

only by the method used to generate a product

not presently regulated might be unduly burdensome. Likewise, applications that are qualitatively

identical to previously approved products, e.g.,

a new ice-minus bacteria application, pose no unexamined risk and should probably be subject to

less review or be exempt.

A priori exclusion from review is problematic

for many scientists. On the other hand, many scientists argue that applications should be assessed

and classified on the basis of certain criteria, and

categories requiring different levels of review be

developed (23,32). This section examines risk

assessment and review considerations for some

types of environmental applications.

Crop Plants and Domesticated

Animals

Genetically engineered crop plants and domesticated animals appear to be the most likely candidates for the category of minimal risk applications for planned introductions. Two important

questions should be considered, however, before

assuming that either type of release is wholly safe:

● Do the engineered crop plants or domesticated animals have relatives that occupy similar ecological niches and are problematic as

weed plants or feral or pest animals?

● Are the engineered organisms toxic to nontarget species?

In addition, altering a fundamental metabolic

process in plants or animals (e.g, plants engineered

to fix nitrogen or mobilize a novel insoluble nutrient) could require special scrutiny. Changing

metabolic processes can perturb critical energy

and nutrient cycles. For example, augmenting nutrient flows might increase freshwater pollution

(see ch. 5).

Finally, changes in mutualistic species of crop

plants or domesticated animals should probably

be carefully examined. Mutualisms-complex interactions in which both species benefit, such as

pollination by insects–are important to ecosystem function (6). Introductions of genetically engineered species that interact as mutualists should

be tested carefully to ensure that they are ecologically equivalent to existing partners.

Nevertheless, despite the reservations of some,

introductions of genetically engineered crop plants

or domestic animals are strong candidates for an

abbreviated review process in the near future.

Pathogens and Pests

Pathogens or pests used for genetically engineered products slated for environmental release

have the potential to affect the environment adversely. The degree of risk associated with importing any genes from pathogens to nonpathogens is also of concern. A distinction, however,

can be made between the genes of a pathogen

that are involved in the disease process and those

that direct basic structural or metabolic functions.

While some would argue that any genes used from

such organisms pose problems, others point out

that general genes of structure and metabolism

are not special in pathogens.

Pathogenicity is known to involve a number of

genes that must be intact and operate in a concerted and coordinated fashion in pathogens

(12,39). The kind of review that relatives of pathogenic species should be subject to is a topic of much

discussion. There are two kinds of relatives of

pathogenic organisms: avirulent strains that differ from the pathogen by only one or a few genes,

and nonpathogenic relatives that contain none of

the disease-causing genes. The effect of genetic

change on these two types of relatives has different potential for undesirable consequences. Nonpathogenic relatives probably have little realistic

chance of acquiring all of the characteristics necessary to become pathogenic (39). That is, because

pathogenicity usually requires the concerted action of several genes, a change in one gene would

not be likely to convert a nonpathogen to a pathogen. Thus, nonpathogenic relatives could require

less review than pathogenic organisms if all other

criteria are equal.

On the other hand, genetic changes can readily

convert some avirulent relatives to virulent pathogens (30,39). In these cases, the relatives are

avirulent forms of the disease causing species and
773

differ from the pathogen by only one or two

changes. For example, changes in virulence have

been described for viral and fungal pathogens.

Temperate viruses that infect bacteria can become

virulent with genetic changes at only one or a few

loci (29). Certain fungal pathogens of plants can

evolve (in response to selection pressure) virulence

characteristics against new cultivatable varieties

within a few years after the new cultivars have

been widely planted (50). Finally, avirulent strains

of a pathogen can recombine within an organism

during an infection to produce lethal recombinant. Recent experiments demonstrated that

two avirulent herpes simplex virus type 1 strains

could interact in vivo to produce virulent recombinant resulting in a lethal infection in mice (21).

Changing a pathogen’s environment or introducing it into a new one could potentially affect

virulence expression or host range—thus arguing against exempting from review proposed releases using pathogens, pests, or avirulent relatives. Artificial and disturbed environments, in

particular, seem likely settings for such shifts in

expressed virulence of a pathogen. Legionella

pneumophila, the causative agent of Legionnaire’s

disease, for example, occurs in natural freshwater

habitats, but can also adapt to life in cooling towers

and other nonnatural aquatic environments from

which it has easier access to humans (43). Similarly, Endothia parasitic (chestnut blight) is an

opportunistic fungal pathogen of several tree species, In its native Asia, the fungus causes little damage, because forest trees have evolved resistance

genes (25). Since its accidental introduction into

North America, the fungus has virtually eliminated

the American chestnut tree throughout its geographic range in the Appalachian mountains because these trees previously had not been pressed

by natural selection to evolve resistance.

Thus, the use of pathogens and some related

avirulent species in environmental applications

could pose special problems. Such releases are

not likely candidates for exemption from review.

However, applications transferring general

genes (genes not involved in causing disease)

from pathogens to nonpathogens do not present pathogen-specific problems. In the absence of evidence indicating special risk factors, such applications could receive a review

less rigorous than one using a pathogen. Finally, although the release of any form of pathogenic organism as a biological control agent is likely

to generate controversy, this is an area where a

mathematical and genetic framework exists for

examining the properties of a pathogen before

release (2)3,22). Furthermore, there is extensive

experience with biocontrol agents, especially in

the use of soil-borne plant pathogens (42).

Molecular Construction of the

Organism

A different approach that could be used to distinguish applications requiring different levels of

review examines the molecular details of the

altered organism’s genetic construction. Such an

examination could include, but not be limited to:

●

●

●

whether the genetically engineered organism

has been constructed using genetic material

from the same genus (intrageneric) or different genera (intergeneric);

whether the alteration of the released organism involves the insertion or deletion of

genetic material; and

whether the alteration of the released organism involves regulatory (not structural or coding) sequences.

Because applications involving genetically engineered micro-organisms have generated much of

the controversy in this area of biotechnology, considerations of these criteria will focus on such applications.

Intrageneric and Intergeneric

Constructions

Taxonomic groupings are in a perpetual state

of flux, with the classification of organisms into

species, genera, and sometimes even higher taxonomic categories often changing as scientists

learn more about the phylogeny of all organisms.

New molecular techniques have changed prior

interpretations of evolutionary relationships—

sometimes radically so. Such realignment is true

for all organisms, including micro-organisms.
114

The degree of relatedness of the genetic material used in genetically engineered organisms has

generated considerable debate. Are intrageneric

organisms so similar to those that already exist

in nature that laboratory derived intrageneric constructions can be exempt from review? Or are the

risks of intrageneric and intergeneric constructions similar, so that they should be reviewed in

a similar manner?

Because the prospects for competition leading

to extinction can be greater for closely related species than for distantly related ones (9), some propose that slightly modified organisms should receive special scrutiny. Others argue that the

designation of genera in microorganisms, and in

bacteria in particular, is often arbitrary and the

concern about any single case should not be on

taxonomic grounds per se, but rather on the ability or inability to cause harm (12).

Intrageneric and perhaps even intraspecific genetically engineered organisms might be expected

to be less affected by any fitness disadvantage arising from changes in the natural balances between

the genetic components of individuals in any population. Hence, they would be more likely to persist in the environment than intergeneric recombinant. Persistence of intergeneric recombinant,

on the other hand, could be less of an issue than

for intrageneric recombinant (27). If persistence

is an important criterion, then taxonomic factors

should be considered.

Gene Deletions

The deletion of an existing gene from an organism is more likely to arise spontaneously in nature than the de novo acquisition of a new characteristic. This class of molecular alterations

probably poses the least risk for adverse consequences resulting from survival and reproduction after release of the engineered organisms. Other considerations, however, such as the

potential for adverse genetic, physiological, and

ecological consequences of the particular application would have to be assessed before such applications could be assumed safe and entirely exempt from review. Nevertheless, some review

requirements are less pertinent to this type of

molecular construction than for those involving

acquisition of new characteristics, and so a modified review process could be appropriate.

Regulatory Genes

Regulatory genes control when and how much

structural gene product a cell makes. The levels

of gene product can affect the expression of individual characteristics, as well as the overall development, structure, function, and vigor of an

organism.

Because gene dosage and timing are important

to an organism’s development, gene alterations

in regulatory sequences are important to changes

in structure and function (from an evolutionary

and ecological standpoint) (5,20). In one example

of tetracycline resistance in the bacterium E. coli,

changes in a regulatory gene result in a 50-fold

difference in the level of resistance to the antibiotic (11). Such changes can also affect the organism’s ability to survive and reproduce in competition with related or neighboring organisms (31).

Regulatory gene changes in recombinant organisms could conceivably not only produce different patterns of gene expression, but also enhance

persistence in the environment. On the other

hand, changes in regulatory sequences that alter

the metabolic regulation of an organism can reduce the organism’s fitness (and thus survivability or persistence).

A pertinent argument has been made that less

concern should be focused on the regulatory gene

than on the trait whose expression is controlled—

some traits being beneficial, while others have the

potential for harm (19). The situations just described illustrate this point. Thus, developing a

strategy to review regulatory gene changes based

on the trait controlled, rather than on the molecular construction of the application, might be

prudent.
115

IDENTIFYING RISKS: MICRO-ORGANISMS V.

MACRO-ORGANISMS

A staggering array of genetically engineered

organisms have been proposed for potential environmental applications (see app. A; 44,46,51). Public concern over this next step in biotechnology

appears greater when the release involves microorganisms. Genetically engineered plants with

plant genes have been field tested with little controversy. Genetically engineered plants with bacterial or fungal genes and genetically engineered

bacteria, on the other hand, have involved more

controversy and have been held up longer in the

regulatory system or in litigation (10). Is this perception of differential risk between micro-organisms and macro-organisms realistic? Are there

actually different risks to releasing genetically

engineered bacteria-, algae, fungi, or viruses

(microorganisms) compared with genetically engineered plants or animals (macro-organisms)?

Ecological Impacts

The obvious distinction between micro-organisms and macro-organisms is their size, and size

may affect the ecological impact of an introduced

organism. For example, larger organisms may

move farther, move more biomass, and cycle more

nutrients (per individual) through an ecosystem.

They are also relatively easier to track and recover

and, in general, biologists know more about their

natural history than they do about microorganisms.

Although the introduction of small organisms

would probably generate less notice than the release of even a few big organisms in the wrong

place, the small organisms are potentially more

difficult to control. The generally more rapid reproductive rates of micro-organisms could allow

Photo credit: Peter Forde, Advanced Genetic Sciences

Some of the equipment set up for monitoring survival and dispersal of ice minus bacteria in

Advanced Genetic Sciences’ first field test.
116

them to proliferate and spread more rapidly

through the environment than larger organisms.

Microorganisms are also harder to retrieve and

exterminate.

Competition

Competitive interactions between newly introduced engineered organisms—either micro- or

macro-organisms-and native organisms are crucial components of ecological impact assessment.

Competition occurs if the released and indigenous

organisms limit each other’s abundance in the

environment without consuming each other. Competition with alien organisms can result in extinction of native taxa (9,28)53). Among plants,

competition-based local extinction appears relatively common (52). Are genetically engineered

micro-organisms better able than macro-organisms to compete with natives?

Most data on this subject have focused on microorganisms. Theories of competition do not suggest any difference between the effects of macroand microorganisms. Those studies that considered competition of micro-organisms also indicated that the principles of competition are universal for both types of organisms (22).

An important issue affecting the impact of released organisms on competitive interactions in

the environment is that the less that is known

about an ecosystem and a species, regardless of

its size, the harder it is to describe competitors.

This factor is not an actual function of the different sizes of micro-organisms v. macro-organisms.

At present, more pertinent information for microorganisms exists, Thus, it should be easier to assess competitive interactions (and adverse consequences) for the release of an altered microorganism.

Cascade Effects

One of the more difficult problems in analyzing the environmental impact of intentionally introduced organisms is the possibility of cascade

effects-changes in one species that destabilize

relationships between other species, leading to

changes in species far removed from the original

disturbance. Cascade effects are the least predictable potential consequences of a planned introduction. Although ecologists have spent a lot of

time examining the structure of communities, it

is still rarely possible to anticipate all the ramifications of introducing or removing a seemingly

innocuous species. Chapter 5 discusses cascade

effects in microbial communities and among

macro-organisms.

Genetic Impacts

In addition to considering different ecological

impacts based on the size of the released organism, important genetic questions should be examined:

● can the organisms exchange genetic information through sexual mechanisms;

● can the organisms exchange genes between

species via nonsexual mechanisms (e.g.,

viruses or plasmids, see ch. 4); and

● does either mechanism carry greater risk of

adverse environmental consequences with

macro-organisms or micro-organisms?

The issue of genetic transfer mechanisms is not

one of differences between macroganisms and

micro-organisms. Instead, it is a question of problems specific to a particular release application,

For example, even for applications that use sexual reproduction as the principal mechanism for

genetic exchange, another factor–the mating

system—must be considered. Species that require

two individuals of opposite sexes to establish a

breeding population do not as readily colonize distant areas as species in which a single individual

can establish a breeding population.

Generalizations about potential genetic impacts,

however, are best applied to well-studied species

of organisms—small or large. Among wild and

little-known species, there are diverse mating systems in both groups, Plants and some vertebrates

are known to exchange genes with members of

other genera, while bacteria in the field might do

little recombining of any sort. Thus, a strategy

to generically assess potential genetic risk on the

basis of a distinction between macro-organisms

and microorganisms would be inadequate.

Evolutionary Impacts

The risks of evolutionary lability in the deliberate release of either micro-organisms or microorganisms should be considered. Neither group
117

is perfectly adapted to its environment. Given real

space and finite populations, any organism is likely

to evolve if presented with an environmental opportunity or challenge (7). An analysis of the environmental risks (including genetic and ecological

risks) would be inadequate if the released taxa

evolved characteristics that were lacking when

the organisms were introduced. The potential for

evolution is a function of both population size and,

most importantly, the selection pressure applied.

Do microorganisms differ from macro-organisms

in their potential to evolve?

Number of Organisms

The number of organisms to be introduced is

a key component in the consideration of evolutionary potentials and impacts. Micro-organisms

and macro-organisms include diverse types with

different potential for invasion and establishment.

In general, the number and the density of organisms involved in a given environmental application will be greater in a release of microorganisms.

This difference in numbers makes the probability of an evolutionary response higher in an introduction that involves micro-organisms. Other

things being equal, the evolutionary risks associated with the environmental release of microorganisms will be greater than those for released

macro-organisms. For example, if mutation occurs

at a rate of one in 107 organisms and if one in

103 of these mutations has an evolutionary impact, the net probability of an environmental impact is one in 1010

. Therefore, a release of 1012

bacteria in a field trial (e.g., 1 liter of 109 organisms per milliliter) could result in an evolutionary impact in that population. However, such a

consequence is unlikely to occur among a release

of only 1O9 organisms.

Selection Pressure

Selection pressure is the most critical component in estimating the probability of adverse evolutionary consequences. In the face of selection pressure, a trait that favors survival and reproduction

(i.e., differential reproductive success) will increase in frequency in the population. Traits conferring disadvantages will be selected against.

Natural selection appears to operate on microorganisms and macro-organisms by the same

mechanisms. But the larger number of microorganisms (by as much as six orders of magnitude) can allow more rapid adaptive responses

since they have shorter generation times and more

genetic variation can be screened in a given

amount of time,

Some applications are more sensitive to selection pressure than others, and this difference

stems mainly from the various uses of engineered

organisms. Again, however, sheer numbers of released organisms could play an important role.

For example, strong selection that eliminates 99

percent of a species will leave behind 10 survivors

of a population of 1,000, and 10,000 survivors of

a population of 1 million. The survivors of such

selection would probably be better adapted, and

a population of 10)000 is more likely to reproduce

itself than is one of 10. Thus, larger populations

(in this case a larger number of released organisms) increase the probability of evolutionary response to selection pressure. The larger numbers

of released organisms that would be associated

with microorganism applications could more

readily evolve in response to environmental selection pressures than the smaller macro-organism

populations.

■ m-. . . . - -... --- . -v- . . . . . . - -

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 1987 Newspaper Enterprise Association, Inc.
118

IMPLICATIONS FOR

Planned introductions of genetically engineered

organisms are the new frontier in biotechnology.

The techniques for exploiting this frontier (e.g.,

recombinant DNA technology and plant cell culture) are well-developed and continue to be refined. But specific data and basic, broad-based

information about many areas necessary to develop capabilities for generic risk assessment

and management strategies are lacking. In

many instances, much of this information can

only be obtained by small= scale, experimental

field testing. Still, controversies surrounding initial applications to release genetically engineered

organisms into the environment have illuminated

areas where research efforts should focus.

Current Status

Although nearly all risk assessments—including

chemical assessments—are and will continue to

be plagued by incomplete data (8), some research

efforts have begun to yield information that is crit -

ical to the examination of potential risks associated with the planned introduction of genetically

engineered organisms. As the data compiled from

small-scale field trials increase, regulators can develop and refine the risk management process.

The charge of funding research efforts to enhance

risk assessment of environmental applications of

genetically engineered organisms falls principally

to three Federal agencies: the Environmental Protection Agency (EPA); the U.S. Department of Agriculture (USDA); and the National Science Foundation (NSF).

Environmental Protection Agency

EPA funds biotechnology risk assessment research through the Office of Research and Development. At EPA, all biotechnology research

projects—intramural and extramural—involve risk assessment. Funding in fiscal year

1986 totaled $4.4 million; in fiscal year 1987 it

reached $5.7 million (26). Table 6-1 lists some of

the types of projects being funded by EPA to develop an adequate scientific database that will allow prediction of environmental risks possibly

associated with the deliberate release of genetically engineered organisms. In a recent solicitaA RESEARCH AGENDA

Table 6.1.—Types of U.S. Environmental Protection

Agency Biotechnology Risk Assessment Projects

●

●

●

●

●

●

Methods for assessing the fate of genetically

engineered micro-organisms in the soil

Methods for detecting, identifying, and enumerating

genetically engineered bacteria in the soil

Survival, modification, and effects of genetically

engineered micro-organisms in aquatic environments

Genetic transfer in aquatic environments

Fate and effects of genetically engineered microorganisms on ecological processes

Fate and effects of genetically engineered microorganisms in simulated natural environments

SOURCE: Office of Technology Assessment, 1988,

tion for research grant proposals, EPA identified

ecological risk assessment, ecosystem structure

and function, and ecological and toxicological effects as priority areas (49).

Federal law limits the scope of EPA’s biotechnology research efforts to those program projects

designed to assist other EPA sectors to perform

their missions. Nevertheless, the range of research

projects that the Agency funds should provide valuable data and should advance in the field of biotechnology risk assessment and risk management

generally.

U.S. Department of Agriculture

Biotechnology research performed by or for

USDA is administered chiefly through the Agricultural Research Service and the Cooperative

State Research Service. Direct risk assessment

components of research represent only a small

fraction of the biotechnology projects at either

agency (4,47). No clear direction to increase or

promote risk assessment aspects of biotechnology research at USDA exists (4). Recent reports,

however, indicate that the Department plans to

increase the profile and funding in its research

agenda of aspects specific to biotechnology risk

assessment (18).

National Science Foundation

From 1 to 13 percent of biotechnology projects

funded by NSF relate directly to risk assessment

(47). Equally as important as funding for direct

biotechnology risk assessment, however, is NSF

funding for research projects to develop the fun-
119

damental scientific database needed for appropriate risk strategies. NSF supports projects in several key areas, including microbial ecology, the

ecology of genes and plasmids, evolutionary biology, and systematic. Additionally, NSF has issued

a program solicitation to establish Biological Facilities Centers and Biological Research Centers

(35), one of which is to be devoted to biotechnology risk assessment (24).

Finally, NSF, USDA, and the U.S. Department

of Energy have undertaken a joint initiative for

plant science centers beginning in fiscal year 1988

(34). Successful initiatives might involve examining responsible application of genetic engineering to avoid undesirable environmental effects or

clarifying ecological processes in agroecosystems

and (34).

Research Needs For the Future

Several permits for small-scale field tests of environmental applications of biotechnology are in the

regulatory approval process or have been been

approved and conducted (see ch. 3 and app. A).

While the information and data gained from these

experiments will be valuable in designing future

risk assessment and risk management protocols,

an expansion of basic scientific research to gather

data critical to risk assessment is also necessary.

Billions of dollars are being invested throughout

U.S. industrial sectors to comply with various environmental standards, but comparatively little is

being invested specifically to improve the scientific basis for the standards (8). An improvement

in risk assessment would be a major step in ensuring that compliance money is well spent (8).

Important areas of research include:

● Taxonomy and Systematics.—gathering

data on the classification and evolutionary

●

●

●

relationships of natural populations (especially nontarget microorganisms) should be

emphasized.

Natural History. -collecting data on the life

histories of organisms intended for planned

introductions and the organisms with which

they interact is critical, especially for those

with potentially harmful impacts.

Ecology.—the complex interactions of microbes, plants, and animals need to be better

understood so that improved predictive capabilities can be developed. Crop ecology, in

particular, is important because agricultural

uses will be the majority of early applications.

Test Systems.—aquatic and terrestrial laboratory microcosms and mesocosms look

promising for analyzing ecological processes

prior to planned introduction. They need further development and refinement.

However, although increased investment in

specific research areas is critical, the paramount need is to develop interdisciplinary research programs in order to support biotechnology risk assessment. Research in such

programs should be thoroughly integrated, from

hypothesis generation to experimentation and

interpretation of results. Active research cooperation among microbiologists, geneticists, ecologists,

molecular biologists, evolutionary biologists, plant

pathologists, entomologists, agronomists, and epidemiologists should be encouraged. The scientific

data gained through such collaborations would

improve significantly the ability to assess biotechnology risks (37,38)41). Nevertheless, uncertainties and questions in risk assessment of planned

introductions will continue to exist. No amount

of research funding can answer all questions;

tough risk management decisions that weigh benefits against risks will need to be made.

SUMMARY AND CONCLUSIONS

During the 1970s, public concern about the effects of technology on the environment and human health led to the development of methods

to help regulators evaluate and control potential

hazards. More recently, attention has focused on

evaluating risks that might be associated with

planned introductions of genetically engineered

organisms into the environment. The related issue of managing risk has also received public attention.
720

Risk assessment, a process distinct from risk

management, uses scientific data to estimate the

effects of exposure to hazardous materials or

other situations. Derived from a factual base, it

can be qualitative or quantitative, Risk management, on the other hand, weighs policy alternatives to select the most appropriate regulatory

strategy or action, This process depends on the

scientific findings of risk assessment, as well as

the role of the public. It involves the integration

of scientific, social, economic, technical, and political concerns. A key to improving the current

situation is to distinguish between those aspects

of the process that are scientific (risk assessment)

and those that are matters of policy decisions (risk

management).

Although risk assessment of recombinant DNA

technology is not a new issue, the specific application of risk assessment to planned introductions

of genetically engineered organisms has become

a matter of debate. Methods developed in the previous decade for chemical risk assessment have

been suggested as models for assessment of risks

that might result from the planned introduction

of engineered organisms. To date, however, generic risk assessment protocols to analyze the

impacts of genetically engineered organisms

have not been widely agreed upon.

Experiences with historical agriculture applications are pertinent and provide parallel

scientific information for many potential applications. Small-scale, experimental field testing is necessary to improve baseline data for

risk assessment.

At present, some scientists argue that the expectation of safety can best be met by a scientific

review of proposed releases of genetically engineered organisms into the environment on an

adaptable, case-by-case basis, and that at this time

a priori exclusion of any application from review

is problematic. Other scientists hold that a rigid

case-by-case approach could paralyze advances

in planned introductions of genetically engineered

organisms, and that a proper balance between regulation and safety would involve each organism

being assessed and classified (on the basis of scientific criteria) into categories requiring different levels of review. In either case, future experience with the impact of various types of genetically

modified organisms on environmental processes

should result in a safe, streamlined review process for some applications, or a lifting of the requirement for review.

Categories that could be considered for abbreviated review include: crop plants and domesticated

animals, and organisms involving nondiseaseassociated genes or gene deletions. Applications

in which the genetically engineered product is substantially identical in its properties to naturally

occurring genetic variants; that could be produced

with previously existing methods and without being subject to regulation under existing law; that

are already available and approved for field testing; or that contain no new genetic material except marker sequences in noncoding regions probably could warrant abbreviated review or possibly

even exemption.

Ecological, genetic, and evolutionary impacts

that could result from planned introductions of

micro-organisms or macro-organisms are important in assessing risks of an introduction. In general, existing knowledge of macro-organisms

(plants or animals) exceeds information available

for micro-organisms (bacteria, algae, fungi, or

viruses), so less scrutiny might be required to yield

an evaluation of the risks associated with the release of a macro-organism.

Controversies surrounding the initial applications to release genetically engineered organisms

into the environment have illuminated areas

where fundamental knowledge of many systems

is currently lacking. In particular, active research

cooperation among microbiologists, geneticists,

agricultural scientists, plant pathologists, entomologists, agronomists, ecologists, and evolutionary

biologists should be encouraged. Interdisciplinary research is critical to developing adequate risk assessment and risk management

for planned introductions of genetically engineered organisms. To dispel speculation, increasing the general knowledge base about organisms intended for environmental applications is

paramount.
121

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34

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3 7

38

39

Washington, DC, personal communication, May

1987.

Regal, P.J., “Safe and Effective Biotechnology:

Mobilizing Scientific Expertise,” Applications of Biotechnology: Environmental and Policy Issues, J.R.

Fowle, III (cd.) (Boulder, CO: Westview Press, 1987).

Regal, P.J., Klug, M., Sayler, G., et al., “Basic Research Needs in Microbial Ecology for the Era of

Genetic Engineering,” Executive Report of the

April-May 1986 Workshop for the National Science

Foundation, Scottsdale, AZ, 1987.

Riley, M., State University of New York at Stony

Brook, Stony Brook, NY, personal communication,

June 1987, October 1987.

40. Rissler, J., U.S. Environmental Protection Agency,

Washington, DC, personal communication, July

1987.

41. Roberts, L., “Discovering Microbes With a Taste

for PCBS,” Science 237:975-977, 1987.

42. Schippers, B., and Garns, W. (eds.), Soil-Borne Plant

Pathogens (New York, NY: Academic Press, 1979).

43. Selander, R. K., McKinney, R. M., Whittam, T. S., et

al., “Genetic Structure of Populations of Le@”onel/a

pneumophila,” Journal of Bacteriology 163:1021-

1037, 1985.

44. Stern, A. M., “Potential Impacts of Environmental

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48.

49.

50.

51.

52.

53.

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Regulation and Research Needs Applications,” Environmental Management 10:445-453, 1986,

Suter, G. W., II, “Application of Environmental Risk

Analysis to Engineered Organisms,” Engineered

Organisms in the Environment: Scientific Issues,

H.O. Halvorson, D. Pramer, and M. Rogul (eds.)

(Washington, DC: American Society for Microbiology, 1985).

Teich, A. H., Levin, M. A., and Pace, J. H., Biotechnology and the Environment: Risk & Regulation

(Washington, DC: American Association for the Advancement of Science, 1985).

U.S. Congress, General Accounting Office, Biotechnology: Analuysis of Federally Funded Research,

GAO/RCED-86-187, Washington, DC, 1986.

U.S. Congress, Office of Technology Assessment,

Public Perceptions of Biotechnology, OTA-BP-BA45 (Washington, DC: U.S. Government Printing Office, May 1987).

U.S. Environmental Protection Agency, “Solicitation for Research Grant Proposals, ” EPA/600/8-

86/028, September 1986.

Van der Plank, J. E., Disease Resistance in Plants

(San Francisco, CA: Freeman, 1968).

Vidaver, A. K., “Plant-Associated Agricultural Applications of Genetically Engineered Microorganisms: Projections and Constraints, ” Recombinant

DNA Technical Bulletin 8:97-102, 1985.

Wagner, R, H., Environment and Man, 3d ed. (New

York, NY: W.W. Norton & Co., 1978).

Wilson, E. O., The Insect Societies (Cambridge, MA:

Belknap Press, 1971).
Appendixes
Appendix A

Pending and Potential

Planned Introductions of

Genetically Engineered Organisms

The information contained in this appendix is

grouped according to the organism receiving the transferred genetic material, or, in the case of deletions,

the organism from which genetic material is deleted.

Within any given entry, pending applications (those

at or near the field test stage) are described first. In

some cases, material on likely or possible applications

follows. This information was compiled from publicly

available materials, and was last updated in early 1988.

Microbes

Bacteria

Killed Bacteria as pesticide (Mycogen, San Diego,

CA).—Mycogen scientists cloned the delta-endotoxin

gene from Bacillus thuringiensis (BT) and inserted it

into a strain of Pseudomonas via plasmid-mediated

transformation. The Pseudomonas is cultured to produce large amounts of the delta-endotoxin, a protein

that is toxic to lepidoptera larvae. The bacteria are then

killed, their cell walls fixed, and the resulting ‘poison

capsule’ is administered as a topical insecticide. Using

the killed and fixed bacteria as a delivery vehicle increases the longevity of the toxin in the environment.

In other applications the protein is rapidly degraded

by sunlight and other environmental action. Using

killed bacteria also eliminates most containment problems. Small-scale field trials were conducted in test

plots near Orlando, FL.

Toa Gosei Chemical, in Japan, has an active research

program aimed at producing similar killed BT agents.

They are screening natural strains of B. thuringiensis

to identify varieties that will target specific pests (e.g.,

diamond back moth, fabricius, etc.) and cloning the

toxin genes into Escherichia coli and B. subtilis to enhance production (37).

“Ice Minus” (Advanced Genetic Sciences (AGS), Oakland, CA).–AGS researchers have produced strains of

Pseudomonas syringae and P. fluorescent from which

the gene for the ice-nucleation protein has been

deleted. AGS had hoped to field test in early 1986, but

legal challenges, local opposition, and controversy over

unauthorized facilities for pathogenicity tests mandated by the Environmental Protection Agency (EPA)

caused delay. The first field test began on April 24,

1987, near Brentwood, in Contra Costa County, CA.

The bacteria were topically applied to 2,400 strawberry plants to test the degree of frost resistance conferred upon strawberry plants in the 0.2-acre plot, as

well as to monitor such risk assessment parameters

as survival and dispersal. The manipulations involved

do not impart any new genetic information; rather,

they delete existing information. Comparable strains

of bacteria occur naturally, the results of random mutation. Potential for ultimate survival or spread of test

strains has been judged low. There is no likelihood of

novel characters being transmitted to nontarget species. EPA announced approval of the application for

an experimental use permit in February 1987.

A similar experiment was first proposed in 1982 by

Steven Lindow and Nickolas Panopoulos of the University of California at Berkeley to delete the gene for the

ice-nucleation protein from strains of P. syringae and

Erwinia herbicola and field test them for increased

frost resistance of host plant substrates (especially

potato plants). EPA and the Recombinant DNA Advisory Committee of the National Institutes of Health both

approved the proposal. Local opposition and legal challenges by the Foundation on Economic Trends made

a Fall 1986 test impossible. The field test commenced

on 29 April 1987, near Tulelake, CA, with the planting

in a half-acre plot of 2,000 inoculated tubers and 2,000

controls.

"Ice plus” (Snomax Technologies, Oakland, CA).–

Naturally occurring strains of spray-dried P. syringae

(produced by Kodak Bioproducts Division for AGS),

containing high concentrations of the ice-nucleation

protein, are mixed with water and sprayed from snowmaking guns at ski resorts. This procedure is from 20

to 80 percent more efficient than water alone, and has

been tested on ski slopes in Colorado, Michigan, Minnesota, New York, and Vermont. The 1986-87 season

saw large-scale use in a number of resorts (a major

delay until recently has been in production facility

availability and capacity. Use has been approved 011

U.S. Forest Service lands. It is also possible that the

bacterium might be used in a variety of ice-making

applications in the Arctic.

125
126

AGS claims they have also developed a recombinantDNA form of the bacterium that is up to 1,000 times

as effective as the wild-type strain. There are no immediate plans to use this in any environmental applications.

Engineered Microbial Pesticide (Monsanto, St.

Louis, MO).—Monsanto scientists have cloned the deltaendotoxin gene from B. thuringiensis and used transposable elements to install it in the chromosomes of

strains of P. fluorescent, a microbe that colonizes the

surfaces of corn plant roots. In its host, the inserted

gene is expressed and the gene product retains its toxicity. Monsanto plans to inoculate seed corn with the

engineered bacteria in the hope that they will colonize the roots of the developing plant. The insecticidal activity of the protein toxin should then protect

the plant from the corn-root cutworm. Monsanto’s proposed field test would involve planting 27,000 coated

seeds on a l-acre test plot for each of two consecutive

years.

While data on the behavior of transposable elements

in other systems (notably Drosophila) suggest caution

is warranted, potential problems associated with horizontal gene transmission seem to have been preempted

in this case. Monsanto scientists inserted the deltaendotoxin gene into the Pseudomonas chromosome

with a disarmed transposable element-one from

which the transposase gene (necessary for element mobility) was deleted. Insertion was affected with the aid

of a “helper” transposable element, from which one

of the long terminal repeats necessary for insertion

was deleted (25,26,27).

Monsanto has submitted to EPA a proposal for an

Experimental Use Permit for field testing. EPA has

asked for data from additional toxicity protocols, which

are now being performed.

Toxic Waste Disposal.-Bacteria maybe engineered

to enhance or receive capabilities to metabolize or sequester specific toxic wastes, including polychlorinated

biphenyls (PCBS)) polybrominated biphenyls (PBBs), dioxin, oil spills, phenol, pesticides, herbicides, and heavy

metals. A host of bacteria capable of metabolizing

different substrates are known (17). One such bacterium is a strain of Pseudomonas (developed by

Ananda Chakrabarty) that has been given the capability (Plasmid-qmediated) to metabolize several components of crude oil. This may enhance the possibilities

to control oil spills biologically. It differs from established techniques by combining several different carbon degradative pathways into one organism. Existing methods generally use a mixture of naturally

occurring bacteria each with the capacity to metabolize a different crude ail component, EPA researchers

in Gulf Breeze, FL, have developed systems capable

of degrading jet fuel, 2)4,5-T (the active ingredient in

Agent Orange), trichloroethylene (a solvent that is the

most common ground water contaminant), and pentachlorophenol (PCP, a common wood-treatment

chemical).

Many naturally occurring bacteria have the ability

to degrade a variety of chemicals found in toxic waste.

These abilities could be enhanced both by classical

selection and genetic engineering. Species of Achromobacter are able to degrade carbofuran, a pesticide

against corn rootworm and other crop pests. Flavobacterium species are known to degrade coumaphos, a

pesticide used against livestock pests. An atrazine resistance gene has been isolated from cyanobacteria,

or blue-green algae. Such bacteria maybe engineered

for environmental cleanup programs, such as degrading toxic material remaining in storage tanks where

farmers dump pesticide or herbicide wastes,

The EPA lab at Gulf Breeze has developed a “suicide”

plasmid to ensure that a gene encoding a 3-chlorobenzoic acid-degrading enzyme will be destroyed when

it has served its purpose. The plasmid contains four

elements: the gene for the degradative enzyme, a promoter, a methylase gene, and a restriction enzymeencoding gene. In the presence of 3-chlorobenzoic acid,

the promoter induces production of both the degrada -

tive enzyme and the methylase, which protects the

degradative gene from the action of the restriction enzyme. When the acid has been completely degraded,

methylase production is suppressed, and the restriction enzyme digests the degradative gene. Scientists

believe this type of scheme should be applicable to

many other metabolic pathways, though there are no

imminent plans to field test such microbes.

Toxic Waste Disposal or Heavy Metal Recovery

(Mining). -Bacteria might be engineered to enhance

their abilities to extract or concentrate heavy metal

contaminants from land fills or mine tailings. The bacteria would promote the efficient recovery of minerals,

minimize existing pollution, and leave reclaimed land

usable for agriculture. A number of existing mining

operations use bacteria to aid in the recovery process, such as cobalt extraction with Thiobacillus ferrooxidans. Other potential targets include lead, cadmium, and copper,

Researchers at the EPA laboratory in Gulf Breeze,

FL, are developing bacterial strains resistant to mercury, with the intention of using them to reduce pollution problems in mercury contaminated environments.

It may also be possible to alter some species of algae

to enhance or impart toxic waste disposal ability (see

section on Plants: Engineered Algae),

Pollution Control.-Phosphorus removal, ammonia

oxidation, and flocculation are three significant problems facing municipal water purification systems. Bacteria could be engineered to aid each of these tasks.
127

Miscellaneous—Ecogen (Princeton, NJ) is using both

classical and biotechnological approaches to develop

a variety of novel pesticides. “Plasmid curing” has

produced some new BT toxin vehicles, and recombinant DNA techniques are being used to investigate potential pesticide uses of B. subtilis toxin genes.

After normal drilling operations, as much as 50 percent of the oil may remain in wells, due to capillary

forces and chemical adhesion (8). Engineered bacteria may help extract that remaining oil.

Microbes may be tapped to aid in biomass energy

production, as with yeast engineered to enhance their

ability (generally in contained facilities) to produce

ethanol for fuel. Scientists at the University of Florida

and elsewhere are currently studying this possibility.

Bacteria may also be engineered to enhance their

function in food production processes (28).

Viruse s

Viruses as Pesticides.—By manipulating the organization and expression of baculovirus genomes, researchers hope to increase baculovirus utility as pesticides with specific applications. Commenting on

potential risks, one researcher has said ‘(My guess is

no problem but there are a variety of constructs possible, and some could have broader effects than desired. . . . One can consider many scenarios. In the

worst case (also the most improbable) the situation

could not be corrected. . . . In the course of our studies

already we have developed what we consider improved methods of assessing risks of genetically engineering viral pesticide products. . . . Our methods of

assessing viral gene expression in nontarget hosts are

extremely sensitive” (19). work is being done in this

area by at least three academic groups (in Florida,

Texas, and Georgia) and two commercial companies

(Genetics Institute, Cambridge, MA, and MicroGeneSys, West Haven, CT).

Researchers at the Institute of Virology in Oxford,

England, are pursuing several similar applications. The

first involves a baculovirus that is pathogenic to the

pine beauty moth, Panolis flammea, a pest of lodgepole pine (and other species), especially in northern

Scotland. Field tested viruses contain special marker

nucleotide sequences, to aid in tracking distribution

and dispersal. Although approval has been obtained

from the appropriate regulatory bodies (the Advisory

Committee on Genetic Manipulation of the Health and

Safety Executive, and the Forestry Commission) as well

as the Nature Conservancy Council, delays made testing impossible in 1986. Field tests took place during

1987. (British regulation is largely voluntary, and somewhat more flexible than at present in the United States.)

A similar test to measure viral persistence in a given

ecosystem involved a baculovirus (Autographa californica nuclear polyhedrosis virus) pathogenic to caterpillars of the mottled willow moth, Spodoptera exigua.

This test was carried out by Institute of Virology scientists at an undisclosed United Kingdom site during

the summer of 1986 (3), In both cases, the scientists

anticipate inserting genes to increase the virulence of

the viral pathogen. The gene for the BT delta-endotoxin

is a likely candidate.

Genetics Institute (Cambridge, MA) is pursuing research aimed at inserting an insect toxin gene into a

nuclear polyhedrosis virus. The engineered virus is

targeted at A. californica, an alfalfa pest, as well as

Heliothis species, pests of various crop plants including cotton, soybeans, and rice. Similar work on related

viruses is under way at Tottori University, in Japan.

Commonwealth Scientific and Industrial Research

Organization (CSIRO) researchers in Australia are exploring genetic engineering techniques as a means of

restoring the virulence of the myxoma virus. Originally introduced to control pest populations of introduced rabbits, attenuated forms of the initially virulent virus evolved at the same time rabbits developed

increased resistance. Although the original virus

devasted rabbit populations, the subsequent coevolution between host and pathogen has led rabbit numbers to once again increase. Scientists are attempting

to add a bacterial toxin to the viral genome to increase

its potency (42).

Viruses in Engineered Vaccines.--On 23 July 1986,

the Food and Drug Administration (FDA) announced

approval of “Recombivax HB”, ” a genetically engineered vaccine for hepatitis B, a disease carried by

as many as 200 million people worldwide, 700,000 in

the United States alone. Based on the hepatitis B cell

surface antigen, the vaccine was developed by Chiron

(Emeryville, CA) and marketed by Merck & Co. It has

been shown to produce the same high level of immunity in clinical trials as Merck’s blood-plasma-based vaccine, but without the potential worries associated with

contamination of donated blood by the AIDS (acquired

immunodeficiency syndrome) virus. Several Japanese

groups are working on an engineered hepatitis B vaccine, as are researchers at the Pasteur Institute, Paris;

at Merck, Sharp, & Dohme in West Germany; and at

Smith Kline Biological, Belgium (29).

A cooperative group at the Japan Polio Research Institute and the University of Tokyo Medical School has

recently announced the construction of an attenuated

polio virus vaccine that retains high immunogenicity.

Additional competitors are emerging (40). Japanese research is also focussed on engineered herpes simplex

viruses as vaccines against several human diseases.
128

Chiron is also working on the development of vaccines against hepatitis A, AIDS, malaria, and oral and

genital herpes. In October 1986, Chiron announced

a joint venture (the Biocine Company) with Ciba-Geigy

to produce genetically engineered vaccines.

Researchers at the National Institute of Allergy and

Infectious Disease (NIAID) and elsewhere have inserted

into the vaccinia virus (used originally for smallpox

vaccinations) genes responsible for antigen production

in a number of diseases—herpes simplex, influenza,

hepatitis B, rabies, and respiratory syncitial virus, all

in humans; and vesicular stomatitis in cattle, horses,

and pigs. Vaccinia virus is particularly valuable as a

vector because it needs no refrigeration; it is cheap,

easy to administer, has a large capacity for foreign

DNA; and it has proved safe and effective in over 200

years of use. An early case of inadvertent release involved the accidental vaccination of laboratory researchers during a test in mice of a vaccine for vesicular stomatitis (13).

A vaccine for malaria is being pursued by several

research programs, including groups at New York

University, Chiron, NIAID (working with vaccinia systems), and a collaborative effort by Smith, Kline &

French and the Walter Reed Army Institute of Research. Preliminary human trials began on 17 March

1986, with a vaccine developed by the latter. Early

reports of results were disappointing.

Peter J. Hotez and colleagues at Rockefeller University are developing a vaccine against hookworm, two

species of which (Necator americanus and Ancyclostoma duodenale) cause a substantial public health

problem worldwide. The antigenic determinant for the

vaccine is the histolytic proteolytic enzyme (HP), which

attaches the hookworm to the wall of the small intestine. Synthetic antigen in the vaccine stimulates the

host to produce antibodies to the enzyme. Researchers used phage lambda gt11 to clone the gene for HP

necessary for large-scale production.

Australian scientists at CSIRO, working with Biotechnology Australia and Arthur Webster, two Australian

biotechnology companies, have developed a vaccine

for sheep foot rot, caused by Bacteroides nodosus. The

gene from this bacterium, encoding the production of

the cell surface filaments crucial to infection, was transferred to P. aeruginosa. Inoculating sheep with the

altered P. aeruginosa bacterium stimulates the desired

immune response.

Different groups in the European Economic Community are pursuing engineered vaccines for the

chicken pathogen, infectious bronchitis virus (IBV), foot

and mouth disease, bovine and swine rotavirus, bovine leukemia, avian erythroblastosis, swine pseudora -

bies, and rabies.

Scientists at Baylor University and at Texas A&M

field tested a vaccine for swine pseudorabies in 1984.

An investigation by the National Institutes of Health’s

(NIH) Recombinant DNA Advisory Committee found

the researchers remiss for not having consulted the

local Institutional Biosafety Committees, and concluded

that ambiguities in the NIH guidelines contributed to

confusion in the case. The vaccine was developed by

Novagene, Inc. (Houston) and is now commercially

available through TechAmerica Group, Inc. (Omaha,

NB).

In 1986, researchers from Oregon State University,

at the invitation of collaborators in New Zealand, field

tested an engineered vaccinia virus in that country.

The research was designed to study immunogenicity,

pathogenicity, and transmissibility of a model vaccinia

virus in sheep, calves, and chickens. The engineered

vaccine contained structural genes for proteins from

sindbis virus, a single-stranded RNA virus (31). The researchers found the tests successful.

Scientists from the Wistar Institute (Philadelphia) developed, and collaborators from the Pan American

Health Organization field tested, an engineered vaccinia virus vaccine against rabies in Argentina in 1986

(see ch. 3).

Vaccines (especially those using vaccinia virus) may

be engineered to carry simultaneously the antigenic

determinants for a series of diseases, related or not

(20,30). These vaccines must be monitored carefully,

to avoid the possibility of recombination producing

newly virulent viral forms (12).

In the face of antigenically complex systems, such

as malaria or sleeping sickness, engineered multivalent vaccines may be the only way to provide general

protection. Work is under way to produce such engineered vaccines (4 I), but estimates place successful

completion 10 or more years in the future. However,

preliminary successes with previously refractory diseases, such as schistosomiasis (27), may mean that single antigen approaches might be fruitful against systems once thought amenable only to multivalent

vaccines.

Plants

Herbicide Resistance

Glyphosate. —Scientists at Calgene (Davis, CA) have

inserted the aroA gene from Sahnonella typhimurium

into tobacco to confer tolerance to the herbicide

glyphosate (e.g., Monsanto’s Roundup”). A disarmed

plasmid from Agrobacterium rhizogenes served as the

vector (7). While this gene transfer imparts a new characteristic to strains of an existing plant species, the
129

chance that these characteristics might spread seem

to be very low, if not zero. The U.S. Department of

Agriculture (USDA) approved Calgene’s applications

to field test the altered tobacco plants.

Calgene has patented the aroA gene under the name

GlyphoTol and plans to file applications soon to test

similarly transformed tomato and cotton plants. Corn,

soybean, rape, and some trees are targets of similar

efforts. Calgene has also been working on transforming oil rape (Brassica napus) with a bacterial antibiotic

resistance gene.

Researchers at Monsanto have used the Ti plasmid

from A. tumefaciens to insert genes for glyphosate resistance into tobacco, tomato, and petunia cells from

which resistant plants have been regenerated (34). Field

tests were conducted in the summer of 1987.

Atrazine (Ciba-Geigy).-The herbicide atrazine, manufactured primarily by Ciba-Geigy and marketed as

AAtrex, is degraded very slowly in the environment.

An effective herbicide, annual sales of AAtrex amount

to nearly $250 million, making it the second best selling herbicide after Roundup@. Atrazine is commonly

used on corn, which is naturally resistant. But because

it persists in soil, it can contaminate runoff and reduce yields in sensitive crops that are planted in rotation with atrazine-treated corn, a problem termed

“carry-over.” Several crops are likely candidates for

the induction of atrazine resistance. According to one

estimate, atrazine resistance in the prominent varieties

of soybeans would allow sales of the herbicide to double or triple (2 I). Field tests of engineered atrazine resistance in tobacco were carried out by Ciba-Geigy in

North Carolina in 1986.

The gene for atrazine resistance was transferred by

cross-breeding from bird’s rape (Brassica campestris)

to oil rape, or canola (B. napus), which was field tested

on 30,000 acres in Canada in 1984.

Sulfonylurea (Du Pont).-Genes for resistance or tolerance to the sulfonylureas, such as chlorsulfuron

(Glean, used on grains, especially wheat and barley)

and Oust @ (a broad spectrum herbicide), are the targets of research aimed at producing transgenic plants.

Soil residues of these herbicides can damage crops

grown in rotation, such as sunflowers or soybeans.

Engineering resistance into rotation crops would protect them and expand the market for these herbicides.

Work on this possibility has so far involved the production of plants transformed with resistance genes

introduced into tobacco cells produced in tissue culture. Du Pont, collaborating with Northrup King, field

tested resistant tobacco in 1987.

Miscellaneous.—Researchers at Molecular Genetics

(Minnetonka, MN) are pursuing the induction of resistance to imidazolinone (made by American Cyanamid)

in corn. Approaches based on cell culture and selective breeding are closest to commercialization.

Calgene (Davis, CA) scientists have isolated a gene

conferring tolerance to bromoxynil, a herbicide made

by Rhone-Poulenc Agrochimie, France. Several strategies are being explored to introduce the gene into

sunflower plant cells and other plant tissues. USDA

has approved field tests scheduled for 1988 of tobacco

plants engineered to be tolerant of this herbicide.

In January 1987, scientists at Plant Genetic Systems,

Belgium, reported the genetic engineering of tomatoes,

potatoes, and tobacco plants “totally resistant” to the

broad spectrum herbicide “Basta@, ” produced by

Hoechst AG, Frankfurt am Main, West Germany. The

active ingredient in the herbicide, phosphinotricin, inhibits the plant enzyme glutamine synthetase. Phosphinotricin can be inactivated by acetylation. The gene

for an acetylating enzyme has been isolated from a

strain of streptomyces and inserted into target plants,

protecting them from doses of Basta as high as 10

times those used normally for weed killing (23).

Disease Resistance

Crown Gall Resistant Tobacco (Agracetus, Middleton, WI).—Agracetus scientists used a disarmed Ti plas -

mid to transform tobacco with a gene conferring resistance to crown gall disease. NIH approved the

company’s application for small-scale field testing in

1986, and USDA’s Animal and Plant Health Inspection

Service (APHIS) reviewed the same proposal and certified it as involving “no plant pest risk. ” Field testing

began on 30 May 1986, in Middletown, WI. Agracetus

is pursuing similar ends in corn and soybeans.

Agracetus scientists have also transformed cotton

plants (Gossypium hirsutum) with an antibiotic resistance gene coding for neomycin phosphotransferase

(38).

Engineered Viral Cross Protection (Monsanto/

Washington University St. Louis, MO).—Researchers

at Washington University, in collaboration With Mon -

santo, have engineered cross protection against TMV

in tobacco plants. Resistance to TMV infection was conferred by inserting the TMV coat protein gene into

the tobacco plant genome via the Ti plasmid from A.

tumefaciens (l). Similar results have been achieved

with tomato mosaic virus and alfalfa mosaic virus, suggesting that many plants can be engineered to produce

viral disease resistance. A field test of tomatoes engineered to be resistant to tobacco mosaic virus was approved by USDA and begun on a one-third-acre plot

near Jerseville, IL, on 2 June 1987.

Miscellaneous (Rothamstead Experimental Station,

Harpenden, United Kingdom) .-Researchers have used
130

cell fusion to produce a potato variety resistant to the

potato leaf roll virus. The parental strains are a domestic potato and a wild, South American potato. Britain’s Advisory Committee on Genetic Manipulation approved a field test for the summer of 1987. Also

approved were field tests to be carried out at the Plant

Breeding Institute (Cambridge) of potatoes carrying

two added bacterial enzymes, as models for possible

future improvement efforts.

Pest Resistance

BT Toxin Protected Crops. -In 1985, the Belgian

company Plant Genetic Systems acheived the first introduction of the delta-endotoxin gene from B. thuringiensis into a plant.

Rohm & Haas, collaborating with Plant Genetic Systems, has since used the Ti plasmid to insert the deltaendotoxin gene into tobacco plants, providing protection primarily against the tobacco hornworm, Manduca sexta. Field testing was successfully completed

in 1986 in Dade County, FL, and Bolivar County, MS.

Hybrid seed is expected to reach the market in the

1990s.

Monsanto researchers have recently used the Ti plasmid from A. tumefaciens to insert the BT toxin gene

into tomato plants, to provide protection against lepidopterous pests. Field tests were carried out in the

summer of 1987 (11).

Miscellaneous.—Plant geneticists in England (a collaboration between Agricultural Genetics Company

and the Plant Breeding Institute, both in Cambridge)

have used A. tumefaciens vectors to insert into tobacco

plants a gene coding for a protein that is a natural inhibitor of insect trypsin, a digestive enzyme. The spectrum of insect resistance thus conferred is much

broader than that of BT-toxin-based applications (24).

Seeds might be engineered to produce or increase their

natural production of other “antifeedants,” such as

canavanine, thus reducing losses of stored seeds or

grain to insect pests.

Other researchers at the Plant Breeding Institute

have begun 1987-88 field tests of potatoes into which

a kanamycin resistance gene has been inserted, with

an A. tumefaciens-derived vector, to aid in risk assessment and agronomic studies of transgenic forms of

a well established cultivar.

Tolerance to Environmental Factors

Plants can be engineered to increase their tolerances

to such limiting environmental factors as salinity,

drought, or sensitivity to heavy metal toxicity. This artificial expansion of ecological niches could be exploited

to bring marginal lands into agricultural use or to decrease problems of deforestation and erosion due to

overexploitation (in the Sonora, Great Basin, Negev,

and Sahel, for example).

Nitrogen Fixation Enhancements

The promise of using genetic engineering techniques

to enhance the nitrogen fixation in some plants, and

to bestow it on others, has been highly publicized, Symbiotic bacteria in nodules on the roots of nitrogen-fixing

plants extract gaseous nitrogen from the atmosphere

and convert it to chemical forms accessible to plants.

The biochemical pathways in bacteria that perform

this function usually involve 16 or 17 structural genes

and their associated regulatory sequences, usually referred to as the nif (nitrogen fixing) genes.

BioTechnica International (Cambridge, MA) has produced two potentially commercial strains of Rhizobium

meliloti, a bacterium that forms nodular colonies on

the roots of alfalfa plants. The strains have been engineered to enhance their nitrogen-fixing ability through

the insertion, via disarmed plasmid vectors, of additional copies of their own regulatory genes. The company hopes that 1988 field tests will demonstrate a

15- to 20-percent increase in nitrogen-fixing ability.

British scientists at the Rothamstead Experimental

Station have inserted a marker sequence into a strain

of Rhizobium for a summer 1987 field test to monitor

the extent of gene transfer between rhizobial strains

in soil.

Much of the research aimed at imparting nitrogenfixing ability to plants that do not have it naturally is

focused on transferring the nif genes into the plant.

Formidable technical problems are involved in transferring so much genetic material and ensuring its

proper expression. Substantial progress with this more

generally applicable approach may be 5 to 10 years

away.

Engineered Algae

Donald Cheney and colleagues (Northeastern University, Boston, MA) are using protoplasm fusion techniques

to tailor marine algae (especially Dunaliel/a salina) to

increase the efficiency of production of beta-carotene,

agar, and other algal byproducts, and George Melville

(Australian National University, Canberra, and Westfarmers Algal Biotechnology Pty., Ltd., Perth) are using

recombinant DNA techniques to achieve the same goal.

Michael T. Henzl and Benjamin Greene, at New Mexico State University, have described the ability of the

common alga, Chlorella vulgaris, to sequester gold. Similar abilities to sequester other heavy metals are known

in other alga (36). Genetic manipulation may one day

be able to enhance such abilities.
131

Miscellaneous

Researchers at Michigan Technological University

are exploring the use of Agrobacterium vectors to impart new qualities to larch trees. The objective is to

induce disease and herbicide resistance, making this

rapid growing, genetically malleable conifer more valuable for reforestation programs.

Fungi are being explored, both by classical methods

(David Sands, Montana Sate University) and cell fusion

techniques (Gary Harman, Cornell) as herbicides targeted against Canada thistle and spotted knapweed and

as antidisease agents, respectively. In the latter case,

cell fusion methods were used to produce hybrid

strains of the soil fungus Trichocderma harzianum that

will be applied via inoculation on the seeds of peas and

cucumbers. Field tests at the New York State Agricultural Experiment Station Vegetable Research Farm

near Geneva, NY, will test the ability of the inoculated

strains to protect against diseases such as damping off

and root rot, caused by other fungi. The Environmental

Protection Agency approved the field tests on 8 September 1986.

Japanese scientists have used cell fusion techniques

to produce a hybrid between red and Chinese cabbage,

called "Bio-Hakuran. ” The new plant displays many

characteristics that are intermediate, but it contains

a full chromosomal complement from each parent—

18 and 20, respectively, for a total of 38. Researchers

are developing the hybrid cabbage as a new truck crop.

Genetic engineering may be able to improve the nutritional value of some plants by increasing their content of seed storage proteins and other components—

for example, lysine in corn. Engineering may increase

forage crop efficiency by enhancing digestibility. Plants

might also be engineered to function as producers of

pharmaceuticals or specialty chemicals, such as particular oils or storage lipids (14). Gene engineering of

oil-seed crops for quality and quantity of oils is being done by USDA, Sungene, Calgene, Unilever, and

BioTechnica, Canada.

Animals

Fish

Heat-Shocked Salmon.–Supported partly by the

American Tackle Manufacturers Association, fisheries

researchers in Washington and Michigan are using

heat shock to induce triploidy in developing salmon

embryos (Coho (Oncorhynchus kisutch), and king, or

Chinook (Oncorhynchus tshawytscha)). The chromosomal abnormalities induced by heat shock disrupt normal reproductive cycles, including the spawning runs

that lead to death. Plans are to stock Lake Michigan

with triploid fingerlings in the expectation that more

trophy fish will result. Triploid fish, with their disrupted reproductive cycles, contain no new genetic

material, and cannot produce offspring. One researcher

has suggested that future stocking programs should

use such triploids to eliminate reproductive competition with and potentially negative impacts on the gene

pools of wild salmon (16).

Triploid grass carp, also produced by heat shock,

are being studied for use as aquatic weed control

agents in southern riverways and irrigation systems,

especially in California and Florida (39).

Miscellaneous. -Other work on salmon aims at enhancing growth hormone production, either by introducing foreign structural genes or enhancing the function of existing regulatory genes. Work with striped

bass and trout is attempting to increase their cold tolerance by inserting a gene derived from winter flounder. One researcher has stated that within 5 years it

should be possible “to routinely introduce genetic traits

into cultured and wild fish species” (35). A number of

different laboratories, most outside the United States,

are pursuing work of this sort (15).

Livestock

The technology exists to genetically alter farm animals to improve reproductive performance, weight

gain, disease resistance, or coat characteristics (USDA)

Beltsville; University of Washington; University of

Pennsylvania; CSIRO, Australia)(5). Fertilized embryos

from rabbits, sheep, goats, cattle, and pigs have already

been successfully transformed with human growth

hormone genes (10,18). Scientists in Australia are working on moving sheep growth hormone genes between

different varieties of sheep (9).

A significant body of research is being directed

towards engineering livestock animals to function as

new pharmaceutical sources (6), although aspects of

the isolation and purification of such products remain

to be worked out (4).

Poultry

Researchers in the Poultry Research Laboratory, in

East Lansing, MI, have succeeded in transforming developing chick embryos with the avian leukosis virus

and with chick syncitial reticuloendotheliosis virus,

both common disease-causing organisms in poultry

(32,33). The demonstration of the retroviral vector derived from avian leukosis virus may make it possible

to inoculate chickens against the virus, as well as to

insert other genes of interest, such as those regulating growth or egg production rates or conferring resistance to other diseases.
132

Miscellaneous

Genetic engineering techniques hold promise for

altering insect pests to serve as tools in pest control

or eradication. Sterile male blowflies can be produced

by mutagenesis and selection, These altered flies, expected to help eradicate the pests, were field tested

over 1985-86 on Flinders Island, Australia, by a group

of Australian scientists (22). Efforts to control tephritid

pests with engineered medflies are under way at the

University of Hawaii.

Appendix A References

1. Abel, P. P., Nelson, R. S., De, B., Hoffman, N., et al.,

“Delay of Disease Development in Transgenic

Plants That Express the Tobacco Mosaic Virus Coat

Protein Gene,” Science 232(4751):738-743, 1986.

2. Balloul, J. M., Sondermeyer, P., Dreyer, D., et al.,

“Molecular Cloning of a Protective Antigen of Schistosomes,” JVature 326:149-53, 1987.

3. Bishop, D. H. L., “UK release of Genetically Marked

Virus)” Nature 323:496, 1986.

4. Cartwright, T., “Isolation and Purification of Products from Animal Cells,” Trends in Biotechnology

5(1):25-30, 1987.

5. Church, R. B., “Embryo Manipulation and Gene

Transfer in Domestic Animals,” Trends in Biotech -

nolo~ 5(1):13-19, 1987.

6. Clark, A.J., Simons, P., Wilmut, I., et al., “Pharmaceuticals from Transgenic Livestock, ” Trends in

Biotechnology 5(1):20-24, 1987.

7. Comai, L., Facciotti, D., Hiatt, W. R., et al., “Expression in Plants of a Mutant AroA Gene From

SahnoneMi Typhimurium Confers Tolerance to

Glyphosate, ” Nature 317:741-744, 1985.

8. Donaldson, E. C., and Grula, E. A., “There Are Bugs

in My Oil Well)” Chemtech 15(10):602-604, 1985.

9. “Gene Engineers Fashion Giant Sheep,” New Scientist 111(1516):22 July, 1986.

10. Hammer, R. E., Pursel, V.G., Rexroad, C. E., Jr., et

al., “Production of Transgenic Rabbits, Sheep and

Pigs by Microinjection, ’’Nature 315:680-683, 1985.

11. Jacob, M., “Researchers Making Strides in the

Genetic Transformation of Plant Species, ” Genetic

Engineering News 7(7):34-35, 1987.

12. Javier, R. T., Sedarti, F., and Stevens, J. G., “Two

Avirulent Herpes Simplex Viruses Generate Lethal

Recombinant, In Vivo,’’Science 234:746-748, 1986.

13. Jones, L., Ristow, S., Yilma, T., et al., “Accidental

Human Vaccination with Vaccinia Virus Expressing Nucleoprotein Gene, ” Nature 319:543, 1986.

14. Knauf, V. C., “The Application of Genetic Engineering to Oilseed Crops,” Trends in Biotechnology 5:40-

47, 1987.

15.

16.

17.

18.

19.

20.

21.

22.

23.

24.

25.

26.

27.

28.

29.

30.

31,

32,

Maclean, N., Penman, D., and Zhu, A., “Introduction of Novel Genes in Fish, ” Biotechnology

5(3):257-261, 1987.

Mathews, B. E., “50-Pound Kings for Michigan?”

Michigan Out@f-Doors May 1986.

McCormick, D., “One Bug’s Meat. . . .“Bio!TechnolO@ 3:429-435, 1985.

Miller, C., “Growth Hormone Genes Bring Superpigs and Supersheep Closer to Market,” Genetic

Engineering News 7(5):7, 1987.

Miller, L. K., University of Georgia faculty member,

personal communication, 1985.

Moss, B., “Use of Vaccinia Virus Vectors for the

Development of Live Vaccines,” GeneticaZ]y Altered

Viruses and the Environment, Banbury Report No.

22, B. Fields, M.A. Martin, and D. Kamely (eds.)

(Cold Spring Harbor Laboratory, NY, 1985).

Netzer, W.J., “Engineering Herbicide Tolerance:

When Is It Worthwhile? ’’l?ioflechnology 2(11)939-

944, 1984.

New Scientist, Sept. 12, 1985, p. 25.

Newmark, P., “Plant Genetic Systems Gets Basta

Resistance,” BioA’echnology 5:321, 1987.

Newmark, P., “Trypsin Inhibitor Confers Pest Resistance,” Biotechnology 5:426, 1987.

Obukowicz, M. G., Perlak, F.J., Kusano-Kretzmer,

K., et al., “Integration of the Delta -Endotoxin Gene

of Bacillus Thurin@”ensis Into the Chromosome of

Root-Colonizing Strains of Pseudomonades Using

Tn5,” Gene 45:327-331, 1986.

Obukowicz, M. G., Perlak, F.J., Kusano-Kretzmer,

K., et al,, “Tn5-Mediated Integration of the DeltaEndotoxin Gene from Bacillus Thurin&”ensis into

the Chromosome of Root-Colonizing Pseudomonades,” Journal of Bacteriology 168(2):982-989, 1986.

Obukowicz, M. G., Perlak, F. J., Bolten, S. L., et al.,

“IS50L as a Non-Self Transposable Vector Used to

Integrate the BacilZus Thurin@”ensis Delta-Endotoxin Gene into the Chromosome of Root-Colonizing Pseudomonads, ” Gene, in press.

Palca, J., ‘(Genetic Manipulation: Living Outside Regulation,” Nature 324:202, 1986.

“Parisians Put New Hepatitis B Vaccine to Test,”

New Scientist 114(1558):24, Apr. 30, 1987.

Perkus, M. E,, et al., “Recombinant Vaccinia Virus:

Immunization Against Multiple Pathogens,” Science

229(4717):981-984, 1985.

Rice, C. M., Franke, C. A., Strauss, J. H., et al., “Expression of Sindbis Virus Structural Proteins via

Recombinant Vaccinia Virus: Synthesis, Processing, and Incorporation Into Mature Sindbis

Virions,” Journal of Virology 56(1):227-239, 1985.

Saher, D. W., Smith, E.J., Hughes, S. H., et al., “Gene

Insertion Into the Chicken Germ Line by Retroviruses,” Poultry Science 65:1445-1458, 1986.
33. Salter, D. W., Smith, E.J., Hughes, S. H., et al., “Transgenic Chickens: Insertion of Retroviral Genes Into

the Chicken Germ Line, ” Virolo&V 157: in press.

34. Shah, D. M., et al., “Engineering Herbicide Tolerance in Transgenic Plants, ” Science 233:478-481,

1986.

35. Smith, E. T., Durham, A., Terry, E., et al., “How

Genetics May Multiply the Bounty of the Sea, ’’13usiness Week, Dec. 16, 1985.

36. Sutton, C., “Desmids, The Algae With a Taste for

Heavy Metal,” ~ew Scientist 113:45, 1987.

37. Tokyo Nikkei Biotechnology (in Japanese), Nov. 17,

1986, p. 6.

133

38. Umbeck, P., Johnson, G., Barton, K., et al., “Genetically Transformed Cotton (Gossypium Hirsutum

L.) Plants)” Biotechnology 5(3):263-266, 1987.

39. U.S. Department of Agricultural Research Service,

“Putting the Bite on Water Weeds, ” Agricultural

Research 35(5):6-10, 1987.

40. Van Brunt, J., “Hepatitis B Vaccine ItIakers Multiply,” Biotechnology 5(2):103-4, 1987.

41. Walsh, B., “Human Trials Begin for Malaria tTaccine,” Science 235:1319-1320, 1987.

42. “. . . While in Australia, Gene Scientists Fight Back,”

New Scientist 114(1556):13, April 16, 1987.
Appendix B

List of Contractor Documents

For this report, OTA commissioned eight papers on

various topics concerning the planned introduction of

genetically engineered organisms. One was published

as New Developments in Biotechnology, 2—Background

Paper: Public Perceptions of Biotechnology. The

manuscripts of the remaining seven contract documents are available in two volumes from the National

Technical Information Service, 5285 Port Royal Road,

Springfield, VA, 22161 (703) 487-4650.

vol. 1

●

●

Andow, D. A., Snapp, S. S., and Teng, P. S., 1986,

Potential Environmental Impacts of Widespread ●

Releases of Non Ice Nucleating Bacteria in Agriculture.

Upper, C. D., Hirano, S. S., and Vali, G., 1986, An

Assessment of the Impact of Large-Scale Applications of Ice-Minus Bacteria and Other Procedures ●

Designed to Decrease Population Sizes of Ice

Nucleation Active Bacteria on Crops.

●

vol. 2

● Norse, E., 1986, Ecological Issues Relevant to Environmental Application of Genetically Engineered

Organisms. Including:

—Sharples, F. E., Relevance of Lessons From Introductions of Exotic Species.

—Pimm, S. L., and Levin, B. R., Impact on Competitive Abilities of Specific Genetic Alterations.

–Keeler, K., and Dobson, A. P., The Big and Small

of It: Are There Different Risks to Releasing

Genetically Engineered Macro-organisms and

Micro-organisms?

—Lenski, R. E., and Istock, C. A., Are There Specific Genetic Modifications That Are Inherently

So Safe As To Need No Review?

Coleman, D. C., and Hodson, R. E., 1987, An Ecosystems Approach to Potential Perturbations of

Energy Flow and Nutrient Cycles Associated With

Environmental Applications of Genetically Engineered Organisms.

Gosz, J. R., Dahm, C. N., and Flanagan, P. W., 1987,

Ecological Impact of Genetically Engineered Organisms on Ecosystems.

Massey, A., and Gould, F., 1987, The Genetic Basis

of Changes in Host Range or Habitat.

134
Appendix c

Acknowledgments

OTA would like to thank the members of the advisory panel and working group who commented on drafts

of this report, the contractors who provided material for this assessment, and the many individuals and organizations that supplied information for the study. In addition, OTA acknowledges the following individuals for their

comments on drafts of this report:

Edward A. Adelberg

Yale University School of Medicine

New Haven, CT

Brian P. Ager

Advisory Committee on Genetic

Manipulation

London, England

Martin Alexander

Cornell University

Ithaca, NY

Wyatt W. Anderson

University of Georgia

Athens, GA

David Andrews

McCutchen, Doyle, Brown &

Enerson

San Francisco, CA

Charles F. Aquadro

Cornell University

Ithaca, NY

Tamar Barkay

Environmental Protection Agency

Gulf Breeze, FL

Doug Barnett

U.S. Department of Agriculture,

APHIS

Beltsville, MD

John Bedbrook

Advanced Genetic Sciences

Oakland, CA

Fred Betz

U.S. Environmental Protection

Agency

Washington, DC

Wm. Hugh Bollinger

Native Plants Inc.

Salt Lake City, UT

Al Borquin

Ecogen, Inc.

Richland, WA

Winston J. Brill

Agracetus

Middleton, WI

Susan S. Brown

Pioneer Hi-Bred International

Johnstown, IA

William Buhner

Sierra Club

Jackson, MI

Diana Burgwyn

The Wistar Institute

Philadelphia, PA

Terry L. Burkoth

Zoecon Corp.

Palo Alto, CA

Guy L. Bush

Michigan State University

East Lansing, MI

Kate Capps

Ohio State University Press

Columbus, OH

Will D. Carpenter

Monsanto Co.

St. Louis, MO

Donald P. Cheney

Northeastern University

Boston, MA

Robert Clark

Ciba-Geigy Corp.

Greensboro, NC

John J. Cohrssen

Council on Environmental Quality

Washington, DC

Michael C. Coil

Attorney at Law

Bozeman, MT

Rita R. Colwell

University of Maryland

College Park, MD

Robert K. Colwell

University of California

Berkeley, CA

Lyman B. Crittenden

U.S. Department of Agriculture,

Agricultural Research Service

East Lansing, MI

Phil J. Dale

Plant Breeding Institute

Cambridge, England

Bernard D. Davis

Harvard Medical School

Boston, MA

Peter R. Day

Plant Breeding Institute

Cambridge, England

Allen J. Dines

Agracetus Corp.

Middleton, WI

Michael Dover

Peterborough, NH

Jack Doyle

Environmental Policy Institute

Washington, DC

John Duesing

Ciba-Geigy Corp.

Research Triangle Park, NC

Charles Eby

Monsanto Co.

Washington, DC

Albert H. Ellingboe

University of Wisconsin

Madison, WI

Joseph O. Falkinham, III

Virginia Polytechnic Institute and

State University

Blacksburg, VA

Neal Fitzpatrick

The Audubon Naturalist Society

Chevy Chase, MD

135
136

Arnold S. Foudin

U.S. Department of Agriculture

Hyattsville, MD

Gary D. Franc

San Luis Valley Research Center

Colorado State University

Center, CO

Judith Freeman

Department of Agriculture

Olympia, WA

Nicholas M. Frey

Pioneer Hi-Bred International, Inc

Johnston, IA

The Hon. Brian Fresh

Maryland House of Delegates

Annapolis, MD

Clifford Gabriel

Board on Basic Biology

National Research Council

Washington, DC

Don Garling

Michigan State University

East Lansing, MI

William J. Gartland

National Institutes of Health

Bethesda, MD

Sarah L. Gibbons

McCutchen, Doyle, Brown &

Enerson

San Francisco, CA

David Glass

Biotechnica International, Inc.

Cambridge, MA

James Glosser

U.S. Department of Agriculture,

APHIS

Washington, DC

Ray A. Goldberg

Graduate School of Business

Administration

Harvard University

Boston, MA

Rebecca Goldburg

Environmental Defense Fund

New York, NY

Alan Goldhammer

Industrial Biotechnology

Association

Washington, DC

Robert M. Goodman

Calgene, Inc.

Davis, CA

Michael Gough

Bethesda, MD

R. Scott Greer

Genetics Institute

Cambridge, MA

Harlyn O. Halvorson

Brandeis University

Waltham, MA

Pat Helm

Embassy of New Zealand

Washington, DC

Anne K. Hollander

Conservation Foundation

Washington, DC

Dennis E. Hruby

Oregon State University

Corvallis, OR

Donald F. Husnik

U.S. Department of

Washington, DC

Warren C. Hyer, Jr

Agriculture

Association of Biotechnology

Companies

Washington, DC

LaMar J. Johnson

Idaho National Engineering

Laboratory

Idaho Falls, ID

Daniel Jones

U.S. Department of Agriculture

Office of Agricultural

Biotechnology

Washington, DC

Rosamond Katz

U.S. General Accounting Office

Washington, DC

Arthur Kelman

University of Wisconsin

Madison, WI

Jamie Kenworthy

Michigan Strategic Fund

Lansing, MI

Andrew Kimbrell

Foundation on Economic Trends

Washington, DC

Lloyd Kunimoto

Calgene, Inc.

Davis, CA

Jan Kurtz

Scientific Advisory Board

U.S. Environmental Protection

Agency

Washington, DC

Dan Laster

U.S. Department of Agriculture

Agriculture Research Service

East Lansing, MI

Timothy D. Leathers

U.S. Department of Agriculture

Agriculture Research Service

Peoria, IL

Morris A. Levin

U.S. Environmental

Agency

Washington, DC

Steven E. Lindow

Protection

University of California

Berkeley, CA

Frances Mann

U.S. Environmental Protection

Agency

Washington, DC

Amy Mathews

Ecological Society of America

Washington, DC

Lynne McAnelly

Department of Agriculture

Austin, TX

Terry C. McIntyre

University of Waterloo

Waterloo, Ontario, Canada
737

John F. McKeogh

Rohm & Haas Co.

Philadelphia, PA

Margaret G. Mellon

National Wildlife Federation

Washington, DC

Elizabeth Milewski

U.S. Environmental protection

Agency

Washington, DC

David W. Miller

Genetics Institute

Cambridge, MA

Henry Miller

U.S. Food and Drug

Administration

Rockville, MD

Larry Wr

. Moore

Oregon State University

Corvallis, OR

Phyllis Moses

Board on Agriculture

National Research Council

Washington, DC

Neil Nelson

Forgene, Inc.

Rhinelander, WI

Nanette Newell

Synertech Group, Inc.

Research Triangle Park, NC

David Pimentel

Cornell University

Ithaca, NY

David Pramer

Waksman Institute of Microbiology

Rutgers University

Piscataway, NJ

Robert Rabin

National Science Foundation

Washington, DC

Isaac Rabino

Empire State College

New York, NY

Lisa J. Raines

Industrial Biotechnology

Association

Washington, DC

Jeremy Rifkin

Foundation on Economic Trends

Washington, DC

Monica Riley

State University of New York

Stony Brook, NY

Jane Rissler

U.S. Environmental Protection

Agency

Washington, DC

Sarah Robinson

U.S. Department of Justice

Washington, DC

Edward Lee Rogers, Esq.

Washington, DC

Marvin Rogul

University of Maryland

Baltimore, MD

Toichi Sakata

Embassy of Japan

Washington, DC

Douglas J. Sarojak

Advanced Genetic Sciences

Oakland, CA

Russell C. Schnell

University of Colorado

Boulder, CO

Ramon J. Seidler

U.S. Environmental Protection

Agency

Corvallis, OR

Frances E. Sharples

Oak Ridge National Laboratory

Oak Ridge, TN

Gary Stacey

University of Tennessee

Knoxville, TN

William W.M. Steiner

U.S. Department of Agriculture

Agriculture Research Service

Columbia, MO

Guenther Stotzky

New York University

New York, NY

Harlee Strauss

Gradient Corp.

Cambridge, MA

Gary A. Strobe]

Montana State University

Bozeman, MO

Trevor Suslow

Advanced Genetic Science

Oakland, CA

Glenn W. Suter, 11

Oak Ridge National Laboratory

Oak Ridge, TN

Aladar A. Szalay

Boyce Thompson Institute of Plant

Research

Cornell University

Ithaca, NY

Bernard Talbot

National Institutes of Health

Bethesda, MD

Sue A. Tolin

Virginia polytechnic Institute and .

State University

Blacksburg, VA

Jeff Tryens

National Center for Policy

Alternatives

Washington, DC

Peter M. Vitousek

Stanford University

Stanford, CA

E. Blair Wardenburg

Arlington, VA

Lidia S. Watrud

Monsanto Agricultural Products

co.

St. Louis, MO

Edward Wedman

School of Veterinary Medicine

Oregon State University

Corvallis, OR

George A. White

U.S. Department of Agriculture

Plant Introduction Office, ARS

Beltsville, MD

James White

National Pesticide Information

Retrieval Service

Purdue University

Lafayette, IN
138

Louise A. Williams Narendra Yadav Doug Yarrow

Assembly Office of Research E.I., du Pont de Nemours & Co., Embassy of Great Britain

Sacramento, CA Inc. Washington, DC

William H. Wunner

The Wistar Institute

Philadelphia, PA

Wilmington, DE
Appendix D

Glossary of Acronyms and Terms

Glossary of Acronyms

AGS —Advanced Genetic Sciences, Inc.

APHIS—Animal and Plant Health Inspection Service, U.S. Department of Agriculture

BSCC —Biological Sciences Coordinating Committee

BT —Bacillus thuringiensis

CSIRO—Commonweahh Scientific Industrial Research Organization, Australia

DHHS —U.S. Department of Health and Human

Services

DNA —Deoxyribonucleic acid

DOE —Department of Energy

EPA —Environmental Protection Agency

FDA —Food and Drug Administration

FIFRA —Federal Insecticide, Fungicide, and Rodenticide Act

FSIS —Food Safety Inspection Service, U.S. Department of Agriculture

HP —Histo]ytic proteolytic enzyme

IBV —Infectious bronchitis virus

INA —Ice nucleation active

NAS —National Academy of Sciences

NEPA —National Environmental Policy Act

NIAID —National Institute of Allergies and Infectious Diseases

nif —Nitrogen fixation

NIH –National Institutes of Health

NSF —National Science Foundation

OSHA -Occupational Safety and Health Administration

OSTP —Office of Science and Technology Policy

OTA —Office of Technology Assessment

PAHO —Pan American Health Organization

PBB —Poly-brominated biphenyls

PCB —Poly-chlorinated biphenyls

PL —Public Law

PMN —Premanufacture Notice

RAC —Recombinant DNA Advisory Committee,

National Institutes of Health

R&D —Research and development

RNA —Ribonucleic acid

S&E —Science and Education Division, U.S. Department of Agriculture

TMV —Tobacco mosaic virus

TSCA —Toxic Substances Control Act

UK —United Kingdom

U.S.C. —United States Code

USDA —United States Department of Agriculture

UV —Ultra-violet

Glossary of Terms

Aerobic Growth or activity that requires the presence

of free oxygen.

Algorithm: A step-by-step procedure for solving a

problem or modeling a process.

Allele: one of several possible alternate forms of a particular gene (e.g., blue and brown are alleles of the

gene for eye color),

Anaerobic: Growth or activity that does not require

free oxygen.

Anticodon: A triplet of nucleotides on transfer RNA

molecules that binds to the complementary codon

on messenger RNA during the polypeptide -

producing (translation) process. The amino acid carried by the transfer RNA is inserted into the growing polypeptide chain. See codon.

Bacteriophage A virus whose host is a bacterial cell;

also called phage.

Baculovirus: A virus of the family Bacloviridae found

only in invertebrates, and presently being pursued

as a potential biocontrol agent. (See app. A.)

Chloroplast(s): Those structures within plant cells

where photosynthesis occurs; contain small circular DNA molecules that replicate independently.

Chromosome(s): The physical structure(s) within a

cell’s nucleus, composed of DNA-protein complex,

and containing the hereditary material—i.e., genes;

in bacteria, the DNA molecule in a single, closed

circle (no associated protein) comprising a cell’s

genome.

Codon: A series of three adjacent nucleotides in a DNA

molecule that directs (“codes for”) the insertion of

a specific amino acid into a growing protein chain.

Conjugation The reproductive process by which DNA

is transferred between bacteria during cell-to-cell

contact.

Conjugation tube The bridge-like structure by which

cell-to-cell contact is maintained during conjugation.

Conjugative plasmid: A plasmid capable of initiating

and directing the process of conjugation. (Compare

nonconjugative plasmid,)

Convergent evolution: The evolution of similar structures or similar life strategies in unrelated species

because of adaptation in response to similar selection pressures (e.g., in similar ecological habitats).

Cryptic plasmid A plasmid of undetermined function.

Cultivar Often used to refer to plant strains. See

strain.

Cytoplasm: The substance within a cell external

139
140

to the nuclear membrane; pertaining to or contained

in the cytoplasm.

Disarmed transposon: A transposon altered in a manner rendering it incapable of movement, most often

by deletion of the transposase gene, which encodes

the enzyme necessary for excision. (Compare

transposon.)

DNA (deoxyribonucleic acid): The molecule that is the

repository of genetic information in all organisms

(with the exception of a small number of viruses

in which the hereditary material is ribonucleic

acid—RNA). The information coded by DNA determines the structure and function of an organism.

Dominant: An allele or characteristic whose expression prevails over alternatives for a given trait. (Compare recessive.)

Endogenous: Developing or originating within the

organism, or arising from causes within the

organism.

Endotoxin: Poison produced by some gram-negative

bacteria, present in the cellular membrane, and released only upon cell rupture; composed of complex lipopolysaccharide (fat-like molecule + sugar

molecule) and more heat-stable than protein exotoxins. (Compare exotoxin.)

Episome: A DNA molecule that may exist either as an

integrated part of a chromosomal DNA molecule

of the host or as an independently replicating DNA

molecule (plasmid) free of the host chromosome.

Epistasis: The interaction of genes at different loci resulting in the masking of a character.

Epizootic: A disease affecting many animals of one

kind at the same time; analogous to the term epidemic in human populations.

Eukaryote: An organism with membrane-bound,

structurally discrete nuclei and well-developed organelles. Eukaryotes include all organisms except

viruses, bacteria, and blue-green algae. (Compare

prokaryote.)

Exotic Describing a species not originating in the place

where it is found; a nonnative, introduced species.

Exotoxin: A poison excreted by some gram-negative

or gram-positive organisms; composed of protein.

(Compare endotoxin.)

Extrachromosomal DNA DNA not associated with the

chromosome(s) (e.g., plasmid DNA or organelle

(mitochondria or chloroplast) DNA).

Feral: Pertaining to organisms in the wild.

F factor: See fertility factor.

Fertility factor: An episome capable of transferring

a copy of itself from its host bacterial cell (an F +

cell) to a bacterial cell not harboring an F factor (an

F – cell). When the F factor is integrated into the

host chromosome (the resulting cell is called an Hfr

cell), the factor is capable of mobilizing transfer of

the bacterial chromosome to an F – cell.

Gamete: A mature reproductive cell (haploid set of

chromosomes) capable of fusing with a similar cell

of opposite sex to yield a zygote; also called a sex cell.

Gene: The fundamental unit of heredity; an ordered

sequence of nucleotide base pairs to which a specific product or function can be assigned.

Gene family A group of related genes exhibiting a high

degree of homology in function and nucleotide base

sequence.

Gene pool: The sum total of genes in a breeding population.

Gene probe: A molecule of known structure and/or

function used to locate and identify a specific region or nucleotide sequence of a genome; usually

a piece of complementary DNA that has been labeled with a tracer substance, such as a dye or radioactive label.

Genetic code: The manner in which DNA or RNA represents, through chemical subunits, information

that is translated into protein. The genetic code is

read in groups of three nucleotides called codons,

each of which specifies a single amino acid. See also

codon, nucleotide.

Genetic variance: The fraction of the phenotypic variance due to differences in the genetic constitution

of individuals in a population. (Compare phenotypic

variance. )

Genome: The genetic content encoded in a haploid

organism’s genes; in eukaryotes, a haploid set of

chromosomes.

Genotype: The sum total of genetic information contained in an organism; the genetic constitution of

an organism with respect to one or a few loci under consideration. (Compare phenotype.)

Germ line: The earliest, primitive stage of development; pertaining to tissues or cell lineages producing gametes. (Compare somatic. )

Gram-negative/positive: A classification of bacteria

based on differential staining utilizing the GramWiegert procedure. Primarily as a result of an

organism’s cell membrane structure, gram-negative

organisms stain red and gram-positive organisms

stain purple.

High copy number plasmid: A plasmid present in

multiple copies within a single host bacterium. Copy

number (single, low, and high) is dependent on both

plasmid and host cell factors.

Homologous sequence: Nucleic acid segments having an identical or nearly identical linear order of

nucleotide base pairs.

Homology Degree of relatedness in appearance, function, or structure.
141

Horizontal transfer: The passage of genetic material

from one organism to another via nonsexual mechanisms.

Host: In the context of recombinant DNA technology,

the organism used for growth and reproduction of

virus, plasmid, or other foreign DNA source.

Hybridization: A procedure in which single-stranded

nucleic acid segments are allowed to bind to homologous sequences, forming hybrid double-stranded

helices; also, a process (e.g., in plants, producing

offspring resulting from a cross between two genetically unlike entities); the formation of new cells

resulting from fusion of whole cells or cell parts

of different genotypes.

Ice-minus (ice–): A bacterium lacking a functional

gene coding for a protein that promotes the formation of ice crystals by providing a physical nucleus

around which ice crystallizes. The gene has been

deleted from strains of Pseudomonas syringae Pseudomonas fluorescent, and Erwinia herbicola, the

organisms around which debate recently has

focused.

Iceplus (ice+): A bacterium with an intact, functional

ice-nucleating gene.

Introgression: The entry or introduction of a gene

or genes from one population into another (most

often in nature via sexual reproduction, or hybridization).

IS (insertion sequence): One of a class of different

nucleotide sequences found in bacteria that are

capable of spontaneous movement from one chromosomal location to another. Chromosomal material may be mobilized during IS movement; movement may result in mutation at the original and/or

new site(s) of insertion. (Compare transposable

element. )

Line: See strain and cultivar.

Locus (pi. loci): The physical location on a chromosome occupied by a particular gene or its alleles.

LTR (long terminal repeat): One of a class of nucleotide sequences (300-1200 base pairs in length) associated with tumor viruses and cellular oncogenes

that promote gene activity and are similar to transposons. (Compare transposable element.)

Meiosis The process by which chromosomes are

duplicated then divided during the formation of

haploid cells (gametes).

Mendelian: Referring to a trait that is controlled by

a single gene, and that shows a simple dominant/

recessive pattern of inheritance.

Mendelian genetics: Classical method of observing inheritance of a trait (s) in the offspring of crosses between individuals differing in that trait(s); results

in accordance with Mendel’s laws.

Mitochondrion/dria: Those structures within eukaryotic cells where energy is produced and stored;

contains small circular DNA molecules that replicate independently.

Natural selection: The process of differential reproductive success by which genes in a population increase or decrease in frequency with the passage

of generations, depending on their contribution to

the survival of offspring in which they are carried;

arguably the most important of the several mechanisms by which evolution takes place, discovered

by Darwin and first described in 1858-59.

Nonconjugative plasmid: A plasmid incapable of initiating or directing the process of conjugation. (Compare conjugative plasmid.)

Nontransferable plasmid: See nonconjugativeplasmid.

Nucleic acid: A macromolecule composed of sequences of nucleotide bases; DNA or RNA.

Nucleotide (base): The unit of nucleic acids. The

molecules consist of one of four bases—adenine,

guanine, cytosine, or thymine/uracil (DNA/RNA) attached to a phosphate-sugar group. The sugar group

is deoxyribose in DNA; in RNA it is ribose.

Nucleus The membrane-enclosed structure in eukary -

otes that contains the chromosomes.

Organelle: A structure in the cytoplasm of a cell that

is specialized in its ultrastructure and biochemical

composition to serve a particular function (e.g.,

mitochondria, endoplasmic reticulum, chloroplast).

P element: A transposable DNA sequence present in

the fruit fly, Drosophila. (Compare transposon.)

pathogenic: Able to cause disease; often utilized to

express inactivation or lethality.

Phage: See bacteriophage.

Phenotype: The observable characteristics of an

organism produced by the interaction of the genotype and the environment. (Compare genotype.)

Phenotypic variance: The variation among genetically

identical individual organisms in external appearance caused by the interaction of environment with

the genotype during development. (Compare genetic

variance.)

Phylogenetic: Referring to genetic similarities between different organisms as a result of descent

from a common ancestor in evolutionary history.

Plasmid: An extrachromosomal, circular piece of DNA

found in the cytoplasm and capable of replicating

and segregating independently of the host chromosome. (Compare conjugative; cryptic; high copy

number; nonconjugative; nontransferrable plasmid.)

P1eiotropy: The production of diverse phenotypic effects produced by a mutation in a single gene.

Polymerase An enzyme that assembles a number of

similar or identical subunits into a macromolecule

(e.g., DNA polymerase and RNA polymerase).

Primary producer: AI-I organism (plant or micro-
142

organism) that uses photosynthesis to convert solar energy into chemical energy that can be used

by nonphotosynthetic organisms (e.g., humans).

Prokaryote: An organism lacking organelles and

whose DNA is not enclosed within membranebound, structurally discrete nuclei. Bacteria, viruses, and blue-green algae are prokaryotes. (Compare eukaryote.)

Recessive: An allele or characteristic whose expression occurs only in the absence of a dominant trait.

(Compare dominant.)

Recombinant DNA Hybrid DNA sequences assembled

in vitro from different sources; or hybrid DNA sequences from the same source assembled in vitro

in a novel configuration.

Recombination: The formation of a new association

of genetic material; usually applied to the process

of meiosis, during a stage of which the genetic material packaged into gametes is mixed and reconstituted in any of an enormous number of possible

combinations.

Replicon: A genetic element possessing sequences

specifying the initiation and control of the process

by which DNA is precisely duplicated.

Retrovirus: A family of viruses whose genetic material is RNA and is further characterized by the presence of reverse transcriptase in the virion; also

called tumor virus.

Reverse transcripts= An enzyme capable of directing the production of a single-strand DNA copy from

an RNA template.

Rhizosphere: A region of the soil closely surrounding plant roots that is affected by root excretions.

RNA (ribonucleic acid): A molecule existing in three

forms–messenger RNA, transfer RNA, and ribosomal RNA—responsible for translating the genetic

information encoded in DNA into a protein product; the hereditary material of some viruses.

Selective advantage: An organism’s increased probability of reproduction and producing offspring,

conferred by its genetic characteristics.

Selective pressure: The influence of factors extrinsic to an organism (i.e., environmental factors) on

its ability to compete with other organisms for reproductive success.

Sibling species: Independent, reproductive populations that are genetically distinct from one another

yet very closely related, and often difficult or impossible to distinguish by morphological or other

criteria.

Somatic; Pertaining to all diploid cells of an organism

except the germ line. (Compare germ line.)

Species: Taxonomic category subordinate to a genus

composed of individuals with common characteristics that distinguish them from other groups of

the same taxonomic level; in sexually reproducing

organisms, a group of interbreeding natural populations that are genetically distinct from other such

groups.

Strain: A pure culture of organisms within a species,

characterized by one or more particular physical

or genetic properties. See cultivar.

Toxin: See endotoxin and exotoxin.

Transduction: The transfer of genetic material from

one cell to another by means of a virus or bacteriophage.

Transformation: Introduction and assimilation of

DNA from one organism into another via uptake

of naked DNA.

Transposable element: A class of DNA sequences capable of insertion into a genome at numerous positions, and of moving from one area of a genome

to another area or another genome.

Transposase: Enzyme that assists movement of DNA

during the process of transposition.

Transposon: A type of transposable element incapable of autonomous existence, often shuttling genetic

material back and forth between cell chromosomes,

between smaller replicons, and between chromosomes and replicons.

Triplet: Three consecutive bases along a nucleic acid

chain. See codon, anticodon.

Vector: A DNA molecule used to introduce foreign

DNA into host cells.

Vertical transfer: The passage of genetic material

from one organism to another through the germ

line, i.e., sexual mechanisms; in bacteria, through

genome replication and cell division.

Virus: Any of a large group of organisms containing

genetic material but unable to reproduce outside

a host cell.
Index
Index

“AAtrex” (Ciba-Geigy), 129

Administrative Procedure Act, 49

Advanced Genetic Sciences, Inc. (AGS), ice-minus bacteria research by, 40, 49-51, 125

Agracetus Corp. (Middleton, Wisconsin), plant disease resistance research by, 5, 53, 129

Agricultural Genetics Co. (UK), 130

Agriculture

applications of genetically engineered organisms to, 5,

6, 7-8, 16-19, 20, 21-22, 33, 35, 49-57, 60, 86-88,

89-92, 94-95, 96, 125-130

BT use in, 5, 7-8, 18-19, 39, 54, 74, 75, 90, 125, 130

Agrobacterium rhizogenes, 128

Alfalfa mosaic virus, “vaccination” of plants against, 5,

36, 54, 96

Algae

genetic engineering of marine, for mining or mineral

recovery, 38, 97, 126, 130

impacts of planned introductions on local communities

of, 97

Animal and Plant Health Inspection Service (APHIS). See

Department of Agriculture, U.S. (USDA)

Animals

applications of engineered organisms involving, 6-7,

38, 59, 131

engineered vaccines for, 128

gene transfer’s likelihood among, 11, 12, 71, 112

see also Fish; Livestock; Poultry

Antibiotics, bacterial resistance to, 13, 14, 77

Applications, anticipated near-term, of genetically engineered organisms, 3, 5-8, 36-40, 86-87, 91, 93, 94-

95, 96, 97, 125-32

Aquatic life, See Algae; Fish

Argentina, biotechnology-related field testing in, 59, 128

Asilomar Conference (California), 9, 60

Atrazine, developing plant resistance to, 5, 36, 53-54, 89,

129

Australia, biotechnology research in, 127, 128, 130, 131,

132

Australian National University, 130

Autographa California, 127

Bacillus thuringiensis (BT)

delta-endotoxin gene insertion into plants, 5, 7-8, 18-

19, 39, 54, 90, 92, 125, 126, 130

inhibiting gene transfer while transferring toxin gene

of, 15, 74, 80

toxin gene’s insertion into Pseudomonas fluorescent

for pest control, 15, 19, 39, 74, 80, 125, 126, 130

Backus, Richard A., 52

Bacteria. See Micro-organisms; Viruses; individual

bacteria

Bacteroides nodosus, 128

Baculoviruses. See Viruses

“Basta” (Hoechst), 129

Baylor University, 128

Beltsville, Maryland, 131

Benefits

consideration of, in risk management, 22, 109

derived from planned releases, 3, 33, 34, 86, 96, 101,

102

Biocine Co., 128

“Bio-Hakuran, ” 131

Biomass energy, engineered microbes’ aid in producing, ,

127

Biosphere II, 39

BioTechnica, Canada, 131

BioTechnica International, Inc. (BTI) Massachusetts

field test information brochure developed by, 55-5?

nitrogen-fixing research by, 8, 54-55, 63, 96, 130

Biotechnology, Australia, 128

Biotechnology Science Coordinating Committee (BSCC),

27-28, 61

Bolivar County (Mississippi), 130

Borneo, “cascade effect” in, 92-93

Bozeman, Montana, planned introduction in, 58-59

Brentwood, California, “ice-minus” field test near, 51,

125

Calgene, Inc. (Davis, California), herbicide resistance

work by, 5, 128, 129, 131

California

biotechnological field tests in, 49-52, 125

heat-shocked fish in, 131

State biotechnology-related legislative activity in, 50

California, University of-Berkeley, “ice-minus” bacteria

research by, 40, 51, 125

Canada, 129

Carbon cycle, 20, 98

“Cascade effects,” 92-93, 95, 101, 116

Chakrabarty, Ananda, 126

Cheney, Donald, 130

Chiron (Emeryville, California), 127, 128

Chlorella vulgaris, 130

Ciba-Geigy Corp. (Greensboro, North Carolina)

genetically altered vaccine production by, 128

herbicide resistance research by, 5, 53-54

Clemson University (South Carolina), lac ZY marker system research at, 40

Cleveland, Mississippi, planned introduction near, 54

Commonwealth Scientific and Industrial Research Organization (CSIRO), 127, 128

Congress, U. S., policy issues and options for possible action by, 25-29

Construct

importance of understanding, 13, 75

risk assessment and, 113-114

Contra Costa County, California, biotechnological fieldtest in, 51, 125

Coordinated Framework for the Regulation of Biotechnology, 9-11, 45, 51, 52, 60, 61-65, 111

Cornell University 131

145
146

Corn plants

biotechnological protection of, 19, 39, 52-53, 74, 75,

89, 92, 129

see also Agriculture; Crops; Plants

Courts. See Litigation

Crops

increasing genetic variation in, 91

protection, creation, and nutritional improvement of,

by modifying organisms, 5, 7-8, 18-19, 20, 21-22,

35, 37, 89-92, 94-95, 96, 125-130

risk assessments for genetically engineered, 23, 112

see also Agriculture; Plants; individual names of

Crown gall disease, developing plant resistance to, 5, 36,

53, 129

Dade County, Florida, 130

Data

on exotic species survival, 17-18, 85-86, 87

gene transfer agricultural, 15-16, 87

requirements for risk assessment, 23-24, 110, 118-119

Degradation

of toxic compounds by microbial action, 22, 33, 35, 39-

40, 97, 98, 101, 126, 130

see also Pollution

Delta-endotoxin gene. See Bacillus thuringiensis

Denmark, planned introduction legislation in, 65

Density, of engineered organisms and gene transfer, 13,

76

Department of Agriculture, U.S. (USDA), 9, 51, 59, 61-

62, 87, 118, 119

Animal and Plant Health Inspection Service (APHIS),

129

field test regulation by, 51, 53-54, 62, 129, 131

Department of Energy, U.S. (DOE), 119

Department of Health and Human Services, U.S. (DHHS),

60, 61

Du Pont. See E.I. du Pont de Nemours & Co., Inc.

Dutch elm disease, 58-59

Earth First! 52

Ecogen, Inc. (Princeton, New Jersey), 126

Ecological considerations

of planned introduction of genetically engineered

organisms, 3, 4-5, 15, 24, 33, 85-102, 110, 112-114,

115-116

see also Ecosystems; Environment; Genetic considerations; Risks

Economics

of crop loss to frost damage, 20, 40, 94

of engineered organism development, 34

of exotic insect species (US.), 86

of gene insertion for pesticide-resistance, 89-90

see also Funding

Ecosystems

complexity of, and planned introduction’s consequences, 3, 13, 20-22, 93, 97-101

likelihood of planned introductions disrupting, 16, 18,

20-22, 33, 86, 97-101, 112-114

“rate-limiting” elements role in, 98-100

E.I. du Pont de Nemours & Co., Inc. (Wilmington, Delaware), 5, 129

Endothia parasitic, 113

Energy flow, in ecosystem processes, 96, 98-99

Environment

consequences of planned introductions on, 3, 4-5, 7,

15-22, 33, 85-102, 112-116

see also Ecological considerations; Ecosystems; Pollution; Risks

Environmental Protection Agency, U.S. (EPA), 9, 15, 61,

78, 118, 119

biotechnology research application permits regulation

by, 49-51, 52, 53, 54-55, 58, 61, 62, 95, 125, 126,

131

Erwinia, “ice-minus” creation from, 75

Escherichia coli, genetic engineering research using, 7,

73

Ethics, public opinion on biotechnology’s, 9, 46

European Economic Community (EEC), 65, 128

European Parliament, reaction to UK biological release

in, 60

Evolutionary lability, as consideration in biological risk

assessment, 19, 24-25, 90-91

Exotic species, experience with, and relationship to genetically engineered organisms, 17-18, 35, 37, 85-

86, 87, 88

Extrinsic factors

influencing the magnitude, frequency, and stability of

gene transfer, 13, 75-77

see also Ecological considerations; Gene transfer

Federal Insecticide, Fungicide, and Rodenticide Act

(FIFRA)) 9, 49, 58, 61, 62, 63, 64, 65

Fish

genetic engineering to improve, 6, 7, 38, 97, 131

impacts of planned introductions on local communities

of, 97-98

see also Animals

Flinders Island, Australia, 132

Florida

genetic engineering of fish in, 38, 131

planned introduction in, 54, 125

Florida, University of, 126, 127

Food and Drug Administration (FDA), 9, 61, 127

Forest Service, U. S., 125

Foundation on Economic Trends (Washington, DC), biotechnological introductions opposition by, 45, 49,

50, 51, 52, 59, 125

France, planned introduction regulation in, 66

Franklin County, North Carolina, planned introduction

in, 53-54

Funding

biotechnology risk assessment, 118-119

congressional policy options related to research, 25,

28-29

public opinion on Federal Government biotechnological, 47, 48

see also Economics
147

Genera) Accounting Office, U.S. (GAO], 110

Genetic considerations

of planned introduction of genetically engineered

organisms, 11-15, 71-81, 116

in risk assessments, 23, 111, 112-114

see also Ecological considerations; Gene transfer

Genetics Institute (Cambridge, Massachusetts), 127

Gene transfer

consideration of, in risk assessments, 111-112

mechanisms and frequency of, 11-12, 71-77

monitoring, of genetically altered microbes, 13-15, 38,

39, 40, 55, 60, 77-79, 130

potential recipients of, 13, 76

predicting potential effects of, 12-13, 72-77

preventing or reducing, 15, 79-80

see also Genetic considerations

Geneva, New York, 131

Germany, Federal Republic of, biotechnology regulation

in, 66

“Glean” (du Pont), 129

Glyphosate, developing plant resistance to, 5, 36, 89,

128.129

“GlyphoTol” (Calgene), 129

Great Britain. See United Kingdom

Greene, Benjamin, 130

Green Party, 60

Guidelines

biotechnological application, 45

NIH biotechnological, 58-59, 60, 64, 128

Texas biotechnical, 128

see also Regulation; Standards

Gulf Breeze, Florida, 126

Harman, Gary, 131

Hawaii, University of, 132

‘

(Heat shock,” 38, 97, 131

Heavy metal recovery. See Mining

Henzl, Michael ‘I’., 130

Herbicides, developing plant resistance to, 5, 18-19, 36,

53-54, 89-90, 128-129

History

of living organism modification, 3, 5, 7,

natural, of host organisms, 12-13, 73

Hoechst AG (West Germany), 129

Homestead, Florida, planned introduction

Horizontal transfer. See Gene transfer

Hotez, Peter J., 128

“Ice-minus” bacteria

construct importance illustration using,

formation and use of, 7, 20, 40, 94-96

research, 125

“Ice-plus” bacteria, 95, 125

Illinois

field test in, 129

34-36, 87, 94

near, 54

75

State biotechnology-related legislative activity in, 50

Imidazolinones, developing plant resistance to, 36, 129

Impacts of planned release. See Benefits; Ecological considerations; Genetic considerations; Risks

Industry

development of molecular biotechnolo~}~ as an, 3

effects of biotechnological developments on, 35

Insects

genetically engineered to serve as pest controls, 132

impacts of planned introductions on local communities

of, 19, 85-86, 91-93

see also Pesticides

Institute of Virology (Oxford, England), 60, 92, 127

Integrated pest management (1PM), 7, 91

International Conference on Recombinant DNA

Molecules. See Asilomar Conference

Intrinsic factors

influencing the magnitude, frequency, and stability of

gene transfer, 12-13, 73-75

manipulation of, to prevent gene transfer, 79-80

see also Gene transfer

Japan

biotechnology regulation in, 66

biotechnology research in, 125, 127-128

Japan Polio Research Institute, 127

Jerseville, Illinois, field test near, 129

Kodak Bioproducts, 125

Korea, Republic of, 14

Lactobacillus, molecular genetic research using, 7

Lac ZY gene, 13, 40, 78

Lake Michigan, heat-shocked fish stocking of, 131

Legionella pneumophila, 113

Legislation, 9

local biotechnology-related, 50, 51, 53-54

see also Regulation; individual statutes

Life history. See History, natural

Lindow, Steven, 51, 125

Litigation, biotechnology-related, 45, 49, 51, 52

Livestock

bioengineered to produce and store pharmaceuticals,

38, 131

genetic engineering to improve, 6, 59, 131

see also Animals

Los Angeles Times, 59

Louis Harris & Associates, 33, 45

Luciferase gene, 78-79

Manduca sexta, 90, 130

Markers. See Gene transfer; Monitoring

Melville, George, 130

Merck & Co., 127

Merck, Sharp, & Dohme West Germany), 127

Michigan, genetic research on fish in, 38, 131

Michigan Technological University, 131

MicroGeneSys, 127

Micro-organisms

anticipated applications of genetic engineering involving, 7-8, 38-40, 86-87, 93-96

impacts of planned introductions on local communities

of, 19-20, 93-96

see also viruses; individual micro-organisms
148

Middleton, Wisconsin, planned introduction in, 53, 129

Mining, genetically engineered organisms application to,

33, 35, 38, 97, 126, 130

Mississippi, planned introduction in, 54

Missouri, planned introduction in, 52

Models

genetic variation/resistance, 91

life history and population, 24

risk assessment, 110

Molecular Genetics (Minnetonka, Minnesota), 129

Monitoring, genetically altered microbes, 13-15, 38, 39,

40, 55, 77-79, 130

Monsanto Agricultural Products Co. (St. Louis, Missouri)

lac ZY marker system developed by, 13, 40, 78

plant disease resistance research by, 5, 18-19, 36, 52-

53, 92, 126, 129, 130

Montana, planned introduction in, 58-59

Montana State University, 58-59, 131

Monterey County, California, biotechnological field test

in, 49-51

Mutualisms, 112

National Academy of Sciences (NAS), 36, 109

National Environmental Policy Act (NEPA), 49, 51, 60

National Institute of Allergy and Infectious Diseases

(NIAID), 128

National Institutes of Health (NIH)

biological research funding by, 25

biotechnological release approval by, 51, 53, 58-59, 95

guidelines for DNA research by, 9, 58-59, 60, 64, 128

Recombinant DNA Advisory Committee (RAC) of, 51,

53, 60, 128

National Science Foundation, (NSF), 71

research funding by, 118-119

research policies of, 9, 25, 64

Natural history. See History, natural

Nature Conservancy Council, 60, 127

Neisseria gonorrhea, 14

Netherlands, biotechnology research regulation in, 66

New

New

New

New

New

New

Jersey, State biotechnology -related-activity in, 50

Mexico State University, 130

York State Agricultural Experiment Station Vegetable Research Farm, 131

York Times, 59

York University, 128

Zealand, biotechnical field testing in, 59, 128

Nitrogen

cycle, 20-21, 98, 100

fixation, 8, 19-20, 21-22, 38, 54-55, 96, 99-100, 130

North Carolina

planned introduction in, 53-54, 129

State biotechnology-related legislative activity in, 50,

53-54

Northeastern University (Boston, MA), 130

Northrup King, 129

Novagene, Inc., 128

Nutrient cycles, 20-22, 98

Occupational Safety and Health Administration, U.S.

(OSHA), 9, 64

Office of Science and Technology Policy, White House

(OSTP), Coordinated Framework by, 9, 60-61

Oil, engineered bacteria extraction of, 127

Oregon State University, 59, 128

Organization for Economic Cooperation and Development (OECD), safety guideline proposals for biotechnological applications developed by, 45

Orlando, Florida, field trials near, 125

“Oust” (du Pont), 129

Pan American Health Organization (PAHO), 59, 128

Panolis flammea, 127

Panopoulos, Nickolas, 51, 125

Pathogens, risk assessment of genetically engineered

products using, 23, 112

Pepin County, Wisconsin, planned introduction in, 54-55,

63

Personnel, training interdisciplinary scientific, 29

Pesticides

bacteria and viruses use in, 5, 8, 15, 19, 39, 52-53, 54,

74, 75, 89-90, 125, 130

BT toxin gene’s use in, 5, 8, 18-19, 39, 54, 74, 75, 125,

130

viruses as, 8, 19, 39, 60, 92, 127

Phosphonitricin, developing plant resistance to, 36

Plant Breeding Institute (United Kingdom), 130

Plant Genetic Systems (Belgium), 129, 130

Plant Pest Act, 9, 62

Plants

applications of engineered organisms involving, 5, 36-

38, 86-88, 89-91, 93, 94-95, 96, 97, 125-130, 131

bioengineered to produce pharmaceuticals, 131

genetic engineering to increase tolerances to limiting

environmental factors, 130

gene transfer’s likelihood among, 11, 12, 71, 87-88

impacts of planned introductions on local communities

of, 18-19, 89-91

see also Agriculture; Crops; individual species

Policy

issues and options for possible congressional action,

25-29

regulatory agencies planned introduction, 9-11, 64-65

Pollution, control using genetically engineered products,

5, 7, 8, 33, 35, 39-40, 89, 101, 126-127, 130

Populations

decompose, 98, 101

planned introductions’ impact on local, 18-20, 86, 88-

97, 116

size of, and risk assessment, 117

Poultry

engineered vaccines for, 128

genetic engineering to improve, 6, 59, 131

see also Animals

Poultry Research Laboratory (Michigan), 131

Pseudomonas fluorescent

BT toxin gene’s insertion into, 15, 19, 39, 74, 80, 92,

126

‘(ice-minus” research using, 49, 125

survival of, 75-76

Pseudomonas syringae, “ice-minus” research using, 49,

51, 52, 125
749

Public Health Act, 6.5

Public opinion

attitudes, on biotechnological development, 3, 4, 8-9,

10-11, 45-48, 65

role of local, in proposed field tests, 49-60, 65

“Rate-limiting” elements, 98-100

“Recombivax HB, ” 127

Regulation

congressional policy options relating to planned introductions, 25, 27-28

degree of scrutiny in biotechnological, 4, 22, 61

existing framework for planned introduction, 9-11,

60-66

jurisdictional authority regarding, 65

public opinion on biotechnological, 48

relationship between development and stringency of,

34

see also Guidelines; Regulator agencies; Review .

Regulatory agencies

biotechnological policies of, 9-11, 64-65

congressional policy options relating to administrative

mechanisms and powers of, 25, 27-28

review categories establishment by, 4, 111-114, 119

see also Regulation; Review: individual agencies

Research

congressional policy options concerning support of

planned introduction, 25, 28-29

coordinated interdisciplinary, 25, 28, 118-119

future needs in, 4, 119

“ice-minus” bacteria, 7, 20, 40, 94-96

nitrogen fixation, 8, 21-22, 54-55, 96, 99-100

public opinion on biotechnological, 47-48

vector immobilization, 15, 80

Review

approaches to establishing categories for, 4, 23-24,

111-114, 119

congressional policy options relating to planned introductions, 25, 26-27

flexibility of, 8, 22, 111-112

molecular details and level of, 23-24, 113-114

Rhizobium meliloti, nitrogen fixing properties of, 21-22,

54-55, 66, 96, 99-100, 130

Rhome-Poulenc Agrochimie (France), 129

Rifkin, Jeremy, 45

Risk assessment

criteria to consider in, 4, 22, 27, 110

for genetically engineered organisms planned introduction, 4-5, 22-25, 109-114

Risk management, 22, 109-110

Risks

environmental, from planned release, 3, 4-5, 7, 15-22,

33, 86, 97-101, 102, 112-114

genetic, from planned release, 12-15, 72-77, 111-113,

116

of macro-organisms as compared to micro-organisms,

23, 24-25, 115-117

public opinion concerning biotechnological, 3, 4, 8-9,

10-11, 46-47, 48, 49

see also Ecological considerations; Genetic considerations

Rockefeller University, 128

Rohm & Haas Co., plant disease resistance research by,

18-19, 54, 90, 130

Rothamstead Experimental Station (United Kingdom),

129-130

“Roundup” [Monsanto), 128, 129

Saccharomyces cerivisiae, 7

St. Charles County, Missouri, planned introduction in,

52-53

Salinas Valley, California, “ice-minus” field test in, 49-51

Salmonella typhimorium, 7, 128

Sands, David, 131

Screening

for gene transfer discovery, 13-15, 77-79

see also Monitoring

Seeds, protection of, by biotechnological techniques, 37-

38, 91, 130

Selection

human use of, in breeding, 5, 35-36

pressure and resistance evolution, 19, 24-25, 90-91

probability of, and gene transfer, 13, 14, 17, 76-77,

117

Sierra Club, 54

Sirica, John, 51

Small-scale field tests

public opinion and actual experiences with, 49-60

see also locations of individual tests

Smith Kline Biological (Belgium), 127

Smith, Kline, & French, 128

Snomax Technologies (Oakland, California), 125

Soybeans, inoculation with bacteria for increased yields

of, 54, 89

Spodoptera exigua, 127

Standards. See Guidelines; Regulation

Streptococcus, 7

Strobe], Gary, 58-59

“Suicide” bacterium, 15, 80, 126

Sulfonyhrea, developing plant resistance to, 5, 36, 89,

129

Sungene, 131

Sweden, biotechnology regulation in, 66

Taxonomic groupings, for risk assessment, 23, 113-1l4,

119

TechAmerica Group, Inc. (Omaha, Nebraska), 128

Technologies

development of recombinant DNA, 3, 34-35

gene transfer monitoring, 13-15, 77-79, 80

Teitz, William, 59

Texas, State biotechnology-related legislative activity in,

50

Texas A&M University, 128

Thiobacillus ferrooxidans, 126

Tn5, 92

Toa Gosei Chemical (Japan), 12.5

Tobacco mosaic virus (TMV), “vaccinating” plants

against, 5, 129

Tobacco plants, biotechnical herbicide and disease resistance research using, 5, 18-19, 36, 53-54, 89, 90,

129
150

Tokyo, University of, 127

Tomato plants, biotechnological herbicide and disease

protection for, 5, 18-19, 89, 130

Tottori University (Japan), 127

Toxic Substances Control Act (TSCA), 9, 54, 61, 62, 63,

64, 65

Toxic wastes, microbial degradation of, 22, 33, 35, 39-

40, 97, 98, 101, 126, 130

Tracking. See Monitoring; Screening

Training, interdisciplinary scientific personnel, 29

Tulelake, California, “ice-minus” field test in, 51-52, 125

Ultraviolet (UV) light, degradation of BT toxin by, 90

Unilever, 131

United Kingdom (UK)

biotechnology regulation in, 66

planned release in, 60, 92, 127, 129-130

virus resistance research in, 129-130

Vaccine

FDA approval of genetically engineered, 127

inadvertent release of genetically engineered, 128

recombinant DNA developed multivalent, 8, 39, 128

viruses used as, 5, 8, 18-19, 36, 39, 59, 127-128

Vectors, importance of understanding, 13, 15, 75

Viruses

vaccination of plants against, 5, 18-19, 36

as pesticides, 8, 19, 39, 60, 92, 127

as vaccines, 5, 8, 18-19, 36, 39, 59, 127-128

Walter Reed Army Institute of Research, 128

Washington (State), genetic research on fish in, 38

Washington, University of, 131

Washington University (St. Louis, Missouri), plant disease resistance research by, 5, 36, 129

Waterville Township, Wisconsin, planned introduction

near, 54-55

Webster, Arthur, 128

Westfarmers Algal Biotechnology Pty. Ltd. (Australia),

130

West Germany, biotechnology regulation in, 66

White House Office of Science and Technology Policy

(OSTP), Coordinated Framework by, 9, 60-61

Wisconsin

planned introduction in, 53, 54-55, 63

State biotechnology-related legislative activity in, 50

Wisconsin State Journal, 53

Wistar Institute (Philadelphia, Pennsylvania), biotechnical

research by, 59, 128

World Health Organization (WHO), ‘(cascade effect” triggered from spraying program by, 92-93

Yeast

engineered for ethanol production enhancement, 127

molecular genetic research using, 7

Yersinia, gene expression of, 74
"Frankly, I think we'll regret introducing these

organisms into the environment.>)

Drawing by Lorenz; c 1987 The New Yorker Magazine, Inc