Document ID: EPA-HQ-OPP-2004-0182-0006
Agency: epa
Document Type: Supporting & Related Material
Title: 
Posted Date: 2005-10-11T04:00Z

Section
4.0
4
­
1
4
­
Gene
Flow
and
Weediness
4
­
Comment
Excerpts
Commenter
Name:
Tom
Patchett
Commenter
Organization
Name:
Tom
Patchett
Comment
Number:
30509­
014000
Excerpt
Number:
1
Excerpt
Text:
I
am
opposed
to
the
use
of
biotech
expansion
until
some
problems
are
properly
addressed.
This
technology
is
causing
the
bulk
of
the
corn
to
become
infected
with
its
properties
whether
we
wish
it
or
not.
Look
at
the
Star­
Link
infection
in
our
corn
fields.

Please
DO
NOT
APPROVE
more
use
of
this
technology
until
it
is
found
how
to
stop
the
spread
of
the
pollen.
As
a
member
of
The
National
Corn
Growers
Association
and
a
seed
corn
grower
it
is
imperative
to
stop
this
until
more
questions
are
answered.

Commenter
Name:
Ron
Fitchorn
Commenter
Organization
Name:
Illinois
Corn
Growers
Association
Comment
Number:
30509­
104000
Excerpt
Number:
5
Excerpt
Text:
Pollen
drift
has
been
a
key
concern.
Even
with
pre­
commercial
approval,
pollen
drift
from
test
plots
and
hybrid
seed
fields
could
impact
neighboring
fields.
It
is
very
important
that
adequate
safeguards
are
implemented
to
limit
cross­
pollination.

Commenter
Name:
Jim
Diamond
Commenter
Organization
Name:
The
Sierra
Club
Comment
Number:
30509­
105000
Excerpt
Number:
3
Excerpt
Text:
For
instance,
the
Starlink
episode
has
shown
that
genetic
material
can't
be
simply
recalled
but
will
persist.
The
fact
that
many
novel
genetic
"
events"
may
be
introduced
in
the
years
ahead,
and
the
possible
interactions
among
them,
needs
to
be
taken
into
account
­
not
just
the
major
intended
modification
in
single
cases.
Systems
which
are
relatively
stable
with
only
a
few
added
genes
may
turn
out
to
be
far
less
stable
in
a
long­
term
context
with
multiple
genetic
"
events"
subject
to
random
reassortment.

EPA
Response:
The
above
three
commenters
are
concerned
with
pollen­
mediated
gene
flow
from
transgenic
maize
to
nontransgenic
commercial
maize.
Under
FFDCA
and
FIFRA,
the
transfer
of
a
transgene
afforded
the
appropriate
food
tolerance
or
exemption
from
the
requirement
of
a
food
tolerance
and
a
FIFRA
Section
3
registration
does
not
constitute
an
adverse
effect
on
man
or
the
environment
or
result
in
the
food
made
from
such
crops
being
considered
as
adulterated.
The
movement
of
pollen
to
neighboring
fields
is
a
natural
consequence
of
crop
production
and
inevitably
occurs
in
reciprocal
fashion.
Cross­
pollination
of
crops
by
Section
4.0
4
­
2
pollen
from
non­
desired
genotypes
does
not
constitute
a
violation
of
the
laws
governing
plant­
incorporated
protectants,
including
MON
863.
EPA
imposes
appropriate
confinement
conditions
on
field
tests
and
data
gathering
under
experimental
use
permits
(
EUP)
to
prohibit
pollen
flow
before
an
appropriate
food
tolerance
is
issued.
If
the
means
to
prevent
pollen­
mediated
gene
flow
are
not
practical
or
biologically
possible,
the
EUP
is
not
approved.
There
are
no
sexually
compatible
relatives
of
maize
in
the
United
States,
its
possessions
or
territories.
Hence,
the
establishment
of
transgenes
from
transgenic
maize
in
the
environment
is
not
biologically
plausible
within
this
geographic
area.

Commenter
Name:
Charles
Benbrook
Commenter
Organization
Name:
Union
of
Concerned
Scientists
Comment
Number:
30509­
115000
Excerpt
Number:
37
Excerpt
Text:
The
scientists
studied
gene
flow
from
transgenic
sugar
beets
to
Acinetobacter
species
(
common
soil
bacteria)
and
found,
for
the
first
time,
"
transformation
of
naturally
competent
bacteria
by
transgenic
plant
DNA,
even
with
plant
homogenates...."
They
have
also
shown
that
Acinetobacter
bacteria
that
have
taken
up
an
antibiotic­
resistance
gene
from
a
transgenic
plant
can
persist
up
to
two
years
in
soil
(
Gebhard
and
Smalla,
1999).

EPA
Response:
The
study
referred
to
here
was
actually
published
in
1998
(
Gebhard
and
Smalla,
Appl.
Env.
Micro.
64:
1550­
1554).
While
the
authors
did
demonstrate
the
homologous
recombination
of
an
nptII
gene
from
a
plant
transgene
into
a
naturally
competent
strain
of
Acinetobacter
(
BD413),
the
experiments
were
performed
under
optimized
laboratory
conditions
and
may
or
may
not
reflect
the
potential
for
horizontal
gene
flow
from
transgenic
plants
to
soil
bacteria.
Furthermore,
the
detection
of
this
transfer
on
Mueller­
Hinton
Agar
plates
was
reliant
on
the
presence
of
homologous
sequences
being
present
in
the
recipient
organism.
As
the
authors
point
out,
"...
our
findings
should
not
affect
the
evaluation
of
antibiotic
resistance
genes
such
as
nptII
as
markers
in
transgenic
plants.
First,
promoter
sequences,
such
as
NOS
or
TR1/
TR2
are
not
active
in
most
bacteria.
Thus,
transfer
of
the
nptII
gene
from
transgenic
plants
would
not
endow
the
recipient
bacteria
with
a
kanamycin
resistance
phenotype.
Secondly,
most
of
the
antibiotic
resistance
genes
used
as
marker
genes
are
widely
disseminated
in
environmental
bacteria."
It
was
further
concluded
that
if
transformation
were
to
take
place
in
the
soil,
frequencies
would
likely
be
much
lower
than
those
observed
under
these
laboratory
conditions.
While
DNA
may
persist
in
the
soil
for
up
to
two
years
attached
to
a
clay
matrix,
it
is
less
than
clear
that
this
DNA
is
available
to
other
organisms
or
completely
protected
from
nucleases
which
might
degrade
it.
When
soil
organisms
of
all
kind
perish,
their
DNA
is
also
potentially
added
to
the
mix
of
adsorbed
nucleic
acid
which
may
or
may
not
be
accessible
to
soil
microbes.
Additionally,
some
Acinetobacter
spp.
or
at
least
some
strains
of
these
species
appear
to
be
extreme
cases
in
the
sense
that
they
are
more
accepting
of
foreign
DNA
and
maintain
a
competency
(
i.
e.,
ability
to
take
up
DNA)
at
greater
rates
than
other
soil
bacteria.
Most
organisms
rely
on
restriction
systems
to
exclude
foreign
DNA.

Commenter
Name:
Douglas
Tallamy
Commenter
Organization
Name:
University
of
Delaware
­
Department
of
Entomology
and
Applied
Ecology
Comment
Number:
30509­
117000
Section
4.0
4
­
3
Excerpt
Number:
1
Excerpt
Text:
Risk
of
Invasiveness
One
oft­
cited
fear
is
that
genetically
enhanced
corn
will
invade
our
natural
ecosystems
in
much
the
same
way
that
nonnative
plant
species
have
and
with
many
of
the
same
negative
effects.
Or
it
if
doesn't
escape
cultivation
directly,
its
genes
will
through
cross
pollination
with
close
relatives.
Nonsense!
Corn
is
one
of
the
most
genetically
modified
crops
in
the
world;
only
its
modifications
were
achieved
through
thousands
of
years
of
intentional
breeding
that
altered
many
thousands
of
genes
rather
than
a
single
generation
of
change
from
the
introduction
of
a
single
gene
package.
It
is
so
different
from
its
closest
ancestors
that
plant
taxonomists
are
still
unclear
about
what
these
relatives
are.
Corn
is,
in
effect,
a
man
made
species
used
world­
wide,
yet
there
are
no
records
of
it
escaping
cultivation
and
out­
competing
native
plants.
It
is
simply
too
dependent
upon
man's
input
to
survival.
There
are
also
no
records
of
corn
genes
ever
entering
the
genome
of
another
plant
through
cross
pollination.
This
could
only
occur
if
close
relatives
grew
within
a
few
feet
of
corn
plantings.
However,
the
grasses
from
which
corn
was
derived
are
either
extinct
in
the
wild
or
confined
to
a
narrow
range
in
Central
America.
There
is
absolutely
no
threat
of
BT
genes
moving
from
genetically
engineered
corn
to
our
native
flora.

EPA
Response:
There
are
no
sexually
compatible
relatives
of
maize
in
the
United
States,
its
possessions
or
territories
as
stated
above.
Hence,
the
establishment
of
transgenes
from
transgenic
maize
in
the
environment
is
not
biologically
plausible
within
this
geographic
area
as
the
commenter
stated.
The
only
evidence
of
corn
crosspollinating
another
plant
outside
its
genus
are
directed
crosses
between
certain
species
of
Tripsacum,
however,
these
generally
need
to
be
performed
under
laboratory
or
controlled
greenhouse
conditions
and
with
specific
varieties
of
both
species
in
order
for
any
genetic
exchange
to
occur.
When
maize
serves
as
the
female
parent
the
cross
is
more
likely
to
succeed.
Even
then,
it
is
common
for
the
maize
genome
to
be
lost
in
subsequent
generations
due
to
genetic
incongruities
between
the
two
plants.