Adang v. Fischhoff

• Decision Date: 10 April 2002
• Docket Number: No. 01-1169.,01-1169.
• Citation: 286 F.3d 1346
• Parties: Michael J. ADANG and John D. Kemp, Appellants, v. David A. FISCHHOFF and Stephen G. Rogers, Appellees.
• Court: U.S. Court of Appeals — Federal Circuit

Page 1346

286 F.3d 1346

Michael J. ADANG and John D. Kemp, Appellants, v. David A. FISCHHOFF and Stephen G. Rogers, Appellees.

No. 01-1169.

United States Court of Appeals, Federal Circuit.

April 10, 2002.

Oliver R. Ashe, Jr., Greenblum & Bernstein, P.L.C., of Reston, VA, argued for appellants. On the brief were Thomas J. Macpeak, Susan J. Mack, Brett S. Sylvester, and Mark A. Hissong, Sughrue, Mion, Zinn, Macpeak & Seas, PLLC, of Washington, DC.

Roger W. Parkhurst, Parkhurst & Wendel, L.L.P., of Alexandria, VA, argued for appellees. With him on the brief was Charles A. Wendel. Of counsel on the brief was Thomas P. McBride, Jr., Monsanto Company, of St. Louis, MO.

Before GAJARSA, Circuit Judge, FRIEDMAN, Senior Circuit Judge, and LINN, Circuit Judge.

LINN, Circuit Judge.

Appellants seek review of the final decision of the Board of Patent Appeals and Interferences (the "Board") in Interference 103,324 construing Count 1 and, based on this count construction, finding Application 06/848,733, filed on April 4, 1986, by Dr. Michael J. Adang and Dr. John D. Kemp (collectively "Adang"), to be nonenabling, and finding that Adang had not shown actual reduction to practice prior to Fischhoff's November 20, 1986, priority date. Fischhoff v. Adang, Interference No. 103,324 (Bd. Pat. Appeals & Interferences Sept. 29, 2000) ("Board opinion"). Because the Board erred as a matter of law in its count construction, and because Application 06/848,733 is nonenabling even under the correct count construction, and thus is not determinative on priority, we affirm in part, reverse in part, and remand to the Board for further proceedings, consistent herewith, under the correct count construction.

I. BACKGROUND

A. Overview of the Technology

This interference involves tomato plants that have been genetically modified to incorporate a bacterial gene that confers insect resistance. The gene is derived from a strain of the soil-dwelling bacterium Bacillus thuringiensis ("Bt"), which produces one or more crystal proteins that are highly toxic to certain insects. These proteins vary in size and amino acid sequence, but all are originally produced by the bacterium as a protoxin, or inactive form, which is aggregated during the sporulation stage of the bacterial lifecycle to form crystals. When the spores are eaten by an insect, the protoxin is activated by the alkalinity and enzymes of the insect gut. This involves the cleavage of the protoxin into two portions, one or both of which are in the "activated" state that is toxic to the insect ("toxin form"). The activated toxin dissolves the stomach lining of the insect, causing it to die. As a result of this cleavage, the protoxin form differs from the toxin form in molecular weight while the protoxin has a molecular weight of about 130 kD, the activated toxin form has a molecular weight of about 67 kD.

The procedure used to insert the Bt gene into plant cells (termed "transformation") and generate genetically modified plants from the transformed cells (termed "regeneration") is as follows. The gene encoding a Bt protein is initially isolated from a strain of the bacterium and is inserted into a circular piece of DNA termed a "plasmid." Plasmids are small loops of DNA that can be used to transfer a gene of interest between biological systems.

The isolated Bt gene is then transferred to a modified plasmid derived from Agrobacterium tumefaciens, a soil-dwelling bacterium often used in the transformation of plants. This bacterium has a natural ability to inject DNA into the genome of plant cells via plasmids, termed Ti plasmids, that carry genes that can cause tumor formation in plants. The modification of this Ti plasmid is carried out by replacing the tumor-forming genes in the Ti plasmid with foreign genes of interest. By doing this, the modified Ti plasmid is rendered capable of stably integrating into the genome of a host plant and importing the traits of the foreign genes it carries into the host plant.

One important element in such a modified Ti plasmid is a DNA sequence, termed a "promoter," that directs the production of a messenger RNA ("mRNA") copy of the foreign gene (a process known as "transcription"). This mRNA then serves as a template for the production of a growing chain of amino acids that comprise the protein encoded by the gene (a process known as "translation"). The promoter sequence is the site where the cellular transcription machinery initially forms and binds to the DNA.

After the modified Ti plasmid bearing the Bt gene has been produced, it is returned to the Agrobacterium, and a population of these modified bacteria is then brought into contact with tomato cells. The cells are incubated together with the bacteria to allow for the transformation of the cells with the Bt gene. The transformed cells are then cultured to create regenerated tomato plants that produce a Bt crystal protein.

B. Adang's Alleged Conception and Reduction to Practice

Adang alleged the following sequence of events. In 1982, Adang conceived of the idea of genetically modifying plants such that a Bt crystal protein gene would be expressed in plant tissues at levels insecticidal to Lepidopteran insects. In September 1983, Adang succeeded in placing the full length gene (that is, the gene encoding the larger protoxin) into a bacterial expression vector (a DNA molecule allowing the bacterium to express the gene, thus producing protein), which allowed Adang to confirm that the gene had been isolated and actually expressed a protoxin of approximately 130 kD that was insecticidal when eaten by a Lepidopteran insect. By March of 1984, this full length gene had been placed under the control of a promoter sequence allowing expression of the gene by a plant (a "plant-expressible" promoter). By March of 1985, the full length gene and the plant-expressible promoter had been placed into an Agrobacterium vector, and by July of that year, several lines of transformed tomato cells had been developed. Assays in March of 1986 confirmed the production of a Bt crystal protein in the tomato plants regenerated from the transformed cells. Bioassays conducted prior to June 12, 1986, showed that the plants were toxic to Lepidopteran insect larvae.

C. Procedural History

On June 10, 1991, Adang filed Application 07/713,624 ("Adang '91") entitled "Insect Resistant Plants" and directed to the above invention. This application claimed benefit under 35 U.S.C. § 120 of the October 21, 1988, filing date of continuation-in-part Application 07/260,574 ("Adang '88"), the April 4, 1986, filing date of continuation-in-part Application 06/848,733 ("Adang '86"), and the September 26, 1983, filing date of Application 06/535,354 ("Adang '83").

On December 23, 1991, Dr. David A. Fischhoff and Dr. Stephen G. Rogers (collectively "Fischhoff") filed Application 07/813,250 ("Fischhoff '91") entitled "Insect Resistant Tomato Plants," claiming benefit under 35 U.S.C. § 120 of the November 20, 1986, filing date of Application 06/932,818 ("Fischhoff '86").

On February 28, 1994, an Administrative Patent Judge ("APJ") declared this interference between the subject matter claimed in Adang '91 and Fischhoff '91. Count 1 of the interference reads as follows:

A tomato plant which has been regenerated from a tomato plant cell transformed to comprise a full length Bacillus thuringiensis crystal protein gene capable of encoding a Bacillus thuringiensis crystal protein of about 130 kD under control of a promoter such that said gene is expressible in said plant in amounts insecticidal to Lepidopteran insects.

For the subject matter of count 1, the APJ accorded Adang benefit of the October 21, 1988, filing date of Adang '88, and the April 4, 1986, filing date of Adang '86, and accorded Fischhoff benefit of the November 20, 1986, filing date of Fischhoff '86.

On September 29, 2000, the Board issued a Final Decision in the interference. In its decision, the Board construed Count 1 to require that "the tomato plants must produce Bt crystal protein having a molecular weight of 130 kD in amounts sufficient to destroy or control Lepidopteran insects." Board opinion, slip op. at 15 (emphasis added). Specifically, the Board held that

tomato plants encompassed by Count 1(1) must have been regenerated from a tomato plant cell transformed by a full length Bt crystal protein gene which encodes Bt crystal protein of about 130 kD under control of a promoter which directs expression of said structural gene in said tomato plant cell, and (2) must produce amounts of Bt crystal protein protoxin of about 130 kD which destroy or control Lepidopteran insects in any way.

Board opinion, slip op. at 19. Thus, under the Board's count construction, it is insufficient to show merely that the full length gene which is capable of encoding the Bt crystal protein protoxin is incorporated into the tomato plant genome and that the resulting plants are toxic to Lepidopteran insects; rather, the toxic effects must be directly attributable to "Bt crystal protein protoxin of about 130 kD" that is actually produced by the transformed plants in "amounts ... which destroy or control Lepidopteran insects in any way."

In light of this count construction, the Board considered Fischhoff's motion to deny Adang the benefit of the April 4, 1986, filing date of Adang '86. The Board accordingly considered both the adequacy of the written description of Adang '86 and whether that disclosure would have enabled those of skill in the art to practice the invention of the count without undue experimentation.

The Board found that Adang '86 did contain an adequate written description, in that it

(1) describes transformed foreign plant cells using Bt crystal protein genes which encode known Bt crystal proteins which are toxic to Lepidopteran insects under control of a promoter, (2) provides an example ... said to show the successful transformation of cells of at least one of the 94 kinds of...