# Presentation: 139334

## Enablement and Written Description Issues in Utility Plant Applications

**Gary Benzion, Ph.D.**
**Acting Supervisory Patent Examiner**
**AU 1638**

## Art Unit 1638

- Paula Hutzell, Ph.D., SPE (detail Biotech Practice )
- Gary Benzion, Ph.D., Acting SPE
- Amy Nelson, Ph.D., Acting SPE
- Beth McElwain, Ph.D.,Primary Examiner
- David Fox, M.S., Primary Examiner
- Phuong Bui, M.S., Primary Examiner
- Ashwin Mehta, Ph.D., Patent Examiner

- Medina Ibrahim, M.S., Patent Examiner
- Ousama Zaghmout, Ph.D., Patent Examiner
- Cynthia Collins, M.S., Patent Examiner
- Anne Kubelik, Ph.D., Patent Examiner
- Francis Moonan, Ph.D., Patent Examiner
- David Kruse, Ph.D., Patent Examiner

## Overview

- Biological/Technological Factors Affecting Patentability in Plant Biotechnology
- Application of the Standards for Enablement & Written Description Rejections.
- Practical Examples

## Utility Patents for Transgenic Plants

- In 1980,  Diamond v. Chakrabarty established that microorganisms qualify as patentable subject matter.
- To date more than 1600 Utility patents have issued that contain claims to transgenic plants, plant parts and seeds.

## Plant Biotechnology Milestones

- 1983- First plants produced using new biotechnology methods
- 1994- First food product enhanced through biotechnology (FlavrSavr tomato) hits supermarket shelves
- 1995- First soybean developed through biotechnology is introduced
- 1997- U.S. government (APHIS, EPA, FDA) fully approves 18 crop applications of biotechnology
- 1999- Development of “golden rice” that is rich in beta-carotene to help prevent childhood blindness in developing countries
- *From: _Biotechnology Good Ideas are Growing_, Council for Biotechnology Information,April 2000

## Commercial Agricultural Products Overview

## FlavrSavrTM II 

- Used with permission.

## “Wands Factors” In re Wands, 858 F.2d 731, 8 USPQ 2d 1400, (Fed. Cir. 1988)

- Breadth of Claims
- Nature of the Invention
- State of the Prior Art
- Level of Skill in the Art
- Level of Predictability
- Amount of Direction/guidance
- Presence/absence of Working Examples
- Quantity of Experimentation

## Factors Affecting Enablement and Written Description in Plant Biotechnology

- Nature of the Invention
- Plants are not slow-moving animals or large bacteria.  They are highly complex biological organisms comprising a high degree of “junk” DNA vs. structural DNA when compared to animals.
- Level of Predictability/Quantity of Experimentation
- Affected by the large genotype by environment (g x e) interaction
- Drought, high heat, cold, photoperiods sensitivity- complicate gene expression,-- e.g., Oil quality- affected by temperature

## Factors- Cont.

- Predictability/Quantity of Experimentation
- Plants are inter specific and inter genus cross tolerant making new and/or unstable genomes
- e.g., Maize (X) *Tripsacum- *inter species* hybrid**      *wheat x rye*- *inter genus* Tricale*
- Gene expression is affected by the phenomenon of position effect variation.
- Where a gene integrates in a plant genome can be important.
- Large amounts of heterochromatin/methylated DNA regions -can turn off or modify gene expression

## Factors- Cont.

- Are There Working Examples?
- Plants have a high tolerance to chromosome number variation, chromosome inversion and deletions
- Allohexaploid wheat comprises three distinct genomes
- Knock out a gene to silence it in one genome- will the other genes compensate and/or interfere with DNA expression-- unknown!
-  Plants have a high gene copy number- many are pseudo genes
- rDNA in maize varies from 9,000-20,000 copies per line- no correlation to gene copy number and protein expression
- Accordingly, what effect would the insertion of foreign rDNA have on the protein expression in maize?Unknown!

## Factors- Cont.

- Amount of Guidance/Level of Skill in the Art.
- Highly variable in plants
- For example, whole plants can be regenerated from tissue culture. However, tissue culture induces phenotypic variation which can be confounding
- For example, somatic cell variation is not heritable while genetic variation is heritable and both are caused by tissue culture.
- Buffering of genetic abnormalities can be hidden and passed on in later generations due to redundant genetic alleles during chromosome segregation

## Factors- Cont.

- Developmental Specific Expression Can Delay Detection of Variation
- For example, expression during pollen shed, male specific expression absent during male sterility, delayed or aborted flowering, would not be seen in young plants.
- Tissue/Organ Specific Expression
- Expression during pollen or ovule development or during grain fill  (many plants have both sexes in one organism)

## Factors- Cont.

- Breeding or engineering a high level of expression with “always on” promoters may be detrimental.
- Expression of insecticide in absence of insect-- energy drain on plant
- Seed storage proteins- expression only during seed fill
- Oil quality-- changing biochemical pathways only during oil deposition.
- Expression of ripening genes too early can lead to early plant death.

## Sample Utility Plant Specification

- The specification discloses a method of mutagenesis in maize using transposable elements
- One example is provided in which a gene designated (M) is mutated from the recessive allele (m) to a dominant allele (M’) which expresses the recessive phenotype
- M is a common gene found throughout the plant kingdom
- Analysis of this mutation shows the transposable element integrated into gene M- but the gene structure is not known nor is the change known.
- The prior art is completely silent with regard to mutagenesis causing switching of a recessive allele to a dominant phenotype, however, the prior art teaches that transposable elements function by common mechanisms and thus function in most plants and animals
- No further information is provided

## Sample Claims

- 1.  A method of converting a genetic allele to express a recessive phenotype as a dominant allele, comprising:
- 	(A) introducing a transposable element into a plant
- 	(B) producing progeny seed, and
- 	(C) screening progeny from the seed for recessive mutants which express as a dominant allele
- 2.  A plant comprising a mutant gene M’ which expresses the recessive allele (m) as a dominant

## Examiner’s Burden

- It is the examiner’s initial burden to clearly establish any *prima facie* case of lack of enablement and inadequacy of written description in plant biotechnology application by presenting:
- Sound scientific reasoning
- References which buttress the examiner conclusion

## Enablement Requirement 

**35USC § 112, 1st ¶**
- The specification shall ... enable any person skilled in the art to which it [the invention] pertains, or with which it is most nearly connected, **to make and use** the same, . .

## Enablement- Analysis

- 1.  A method of converting a genetic allele to express a recessive phenotype as a dominant allele, comprising:
- 	(A) introducing a transposable element into a plant,
- 	(B) producing progeny seed, and
- 	(C) screening progeny from the seed for recessive mutants which express as a dominant allele.
- 	**Analysis- In View of Wands**
- The invention as claimed is broad, that is,  it is directed to any genetic allele and to any plant, and it is not predictable that an allele other than that taught in the specification can be converted by the method steps in the claim.

## Enablement- Analysis Cont.

- There is no direction in the prior art regarding such allelic conversions or suggestion how to test other transposable element insertions to modify genetic alleles.
- Only 1 working example which does not supply guidance on how to apply the method to other genetic alleles.
- Experimentation to test other genes via the method would be unduly large as the mechanism of the mutation is not known, although this is not a requirement for enablement, in this instance it is difficult to conceptionalize how this invention works and thus how to enable it.
**The method of claim 1 is not enabled as claimed.**

## Tips

- In the absence of other working examples, the specification as filed, should disclose more basic biology concerning M’
- M’could be a point mutation, deletion, truncation, inversion, etc.
- Information on the changes in the gene DNA sequence- if any
- evidence of protein modification/deletion or of changes in the active site of the protein

## Enablement- Analysis Cont..

- 2.  A plant comprising a mutant gene M’ which expresses the recessive allele (m) as a dominant
- _Analysis in view of Wands_
- The M gene is a common gene in plants
- M’ is disclosed in the specification as consisting of the  transposable element integrated into gene M of maize
- Specification teaches that the gene M can be mutated to M’ by insertion of a transposon.  It is not known if this insertion is site specific- although transposons usually insert into specific sequence.

## Enablement- Analysis Cont.

- Other M genes in other species are known to produce the M protein, therefore it is likely that the mutant M’ from maize will function in other plants in a similar fashion.
_**Conclusion**_
- Claim 2 is enabled

## Written Description

**35 USC §112, 1st paragraph**
- The specification shall contain a _written__description_ of the invention. . .

## General Principles- Written Description

- Written description is separate and distinct from the enablement requirement
- Basic inquiry:  can one skilled in the art reasonably conclude that the inventor **was in possession of the claimed invention** **even if every nuance of the claim is not explicitly described in the specification**, at the time the application was filed?

## Written Description Guidelines66 Fed. Reg. 1099 (Jan. 5, 2001)

- Level of Skill and Knowledge in the Art
- Complete or Partial Structure
- Physical And/or Chemical Properties
- Functional Characteristics
- Correlation Between Structure and Function
- Method of Making
- Combinations of the Above

## Written Description Analysis

- Claim1. A method of converting a genetic allele to express a recessive phenotype as a dominant allele, comprising:
- 	(A) introducing a transposable element into a plant
- 	(B) producing progeny seed, and
- 	(C) screening progeny from the seed for recessive mutants which express as a dominant allele
**Analysis- in view of the Written Description Guidelines**
**66 Fed. Reg. 1099 (Jan 5, 2001)**
- What is the level of skill and knowledge in the art
- The structure of neither the M or *M’  *DNA or* * protein is known,
- There is no teaching of how structure affects function- only functional characteristics
- Prior art does not teach other structural changes which have the same functional changes.

## Written Description Analysis- Cont.

- It is unknown if the dominant phenotype is the absence of an M protein or a change in the protein structure- a representative number of species have not been described
- No discussion or knowledge in the art regarding transposons producing this type of mutation
_**Conclusion**_
- The inventor **was not in possession of the method of claim 1 **at the time the application was filed

## Conclusion- Written Description

- Claim 2.  A plant comprising a mutant gene M’ which expresses the recessive allele (m) as a dominant.
- Analysis- in view of the Written description Guidelines **66 Fed. Reg. 1099 (Jan 5, 2001)**
- The claim is limited to the M’ mutant.
- The limitation to “A Plant” is broader than maize- the level of skill and knowledge in the art concerning the expression of a non-native M’ in a plant evidences that it would be expected to function in plants *per se*.
_**Conclusion**_
- The inventor **was in possession of the claimed invention** at the time the application was filed.

## Conclusion- Written Description

**Tips**
- In the specification as filed provide complete or partial DNA structure and protein structure
- Correlate the structural changes to the functional changes
- Determine the physical properties of the gene/protein

## Utility?

- While the invention of claim 1 may be claimed as a method of mutagenesis, the issue of utility would have to be addressed as the specification would have to teach that the method has utility which is:
- Specific.
- Substantial.
- Credible.

## Questions?

- Paula Hutzell 703-308- 4310
- Gary Benzion 703-308-1119
- Amy Nelson   703-308-3218

## Enablement and Written Description Issues in Utility Plant Applications

**Gary Benzion, Ph.D.**
**Acting Supervisory Patent Examiner**
**AU 1638**