Membrane-bound desaturases

• US 6,864,077 B1
• Filed: 12/02/1999
• Issued: 03/08/2005
• Est. Priority Date: 12/03/1998
• Status: Expired due to Fees

• Current Assignee: E. I. du Pont de Nemours and Company (Corteva, Inc.)
• Original Assignee: E. I. du Pont de Nemours and Company (Corteva, Inc.)
• Inventors: Hitz, William D., Cahoon, Rebecca E., Kinney, Anthony J., Cahoon, Edgar B.
• Primary Examiner(s): RAO, MANJUNATH N
• Application Number:
  US09/857,524
• Time in Patent Office: 1,923 Days
• Field of Search: 435/4, 435/6.19, 435/69.1, 435/183, 435/189, 435/252.3, 435/320.1, 435/325, 435/348, 435/410, 435/415, 435/419, 435/426, 536/23.2, 536/23.5, 536/23.6, 536/23.7
• US Class Current: 435/192
• CPC Class Codes: C12N 9/0083 Miscellaneous (1.14.99)

Abstract

This invention relates to an isolated nucleic acid fragment encoding a delta-6 desaturase or sphingolipid desaturase. The invention also relates to the construction of a chimeric gene encoding all or a portion of the delta-6 desaturase or sphingolipid desaturase, in sense or antisense orientation, wherein expression of the chimeric gene results in production of altered levels of the delta-6 desaturase or sphingolipid desaturase in a transformed host cell.

Claims

1. An isolated polynucleotide that encodes a plant sphingolipid desaturase polypeptide having a sequence identity of at least 80%, based on the Clustal method of alignment, when compared to a polypeptide selected from the group consisting of SEQ ID NOs:

2, 4, and 8.

2. The polynucleotide of claim 1 wherein the sequence identity is at least 85%.

3. The polynucleotide of claim 1 wherein the sequence identity is at least 90%.

4. The polynucleotide of claim 1 wherein the sequence identity is at least 95%.

5. The polynucleotide of claim 1 wherein the polypeptide is selected from the group consisting of SEQ ID Nos:

2, 4, and 8.

6. The polynucleotide of claim 1, wherein the polynucleotide is selected from SEQ ID Nos:

1, 3, and 7.

7. An isolated complement of the polynucleotide of claim 1, wherein (a) the complement and the polynucleotide consist of the same number of nucleotides, and (b) the nucleotide sequences of the complement and the polynucleotide have 100% complementarity.

9. A recombinant DNA construct comprising the polynucleotide of claim 1 operably linked to at least one regulatory sequence.

10. The recombinant DNA construct of claim 9, wherein the recombinant DNA construct is an expression vector.

11. A method for altering the level of plant sphingolipid desaturase polypeptide expression in a host cell, the method comprising:

(a) transforming a host cell with the recombinant DNA construct of claim 9; and

(b) growing the transformed cell in step (a) under conditions suitable for the expression of the recombinant DNA construct.

12. A method for transforming a cell comprising introducing into a cell the recombinant DNA construct of claim 9.

13. A method for producing a transgenic plant comprising (a) transforming a plant cell with the recombinant DNA construct of claim 9, and (b) regenerating a plant from the transformed plant cell.

14. A method for producing gamma linolenic acid in soybean plants, the method comprising (a) transforming a soybean cell with the recombinant DNA construct of claim 9, and (b) regenerating transgenic plants from the transformed cell of (a), wherein plants comprising the recombinant DNA construct of claim 9 produce gamma linolenic acid which is normally not produced in soybean plants.

15. The polynucleotide of claim 1 wherein the sphingolipid desaturase is a delta-6-desaturase.

16. A transgenic cell comprising the recombinant DNA construct of claim 9.

17. The cell of claim 16, wherein the cell is selected from the group consisting of a yeast cell, a bacterial cell, an insect cell, and a plant cell.

8. An isolated sphingolipid desaturase polypeptide having a sequence selected from the group consisting of SEQ ID NOs:

2, 4, and 8.