Delta-8 desaturase and its use in making polyunsaturated fatty acids
Isolated nucleic acid fragments and recombinant constructs comprising such fragments encoding a delta-8 desaturase along with a method of making long-chain polyunsaturated fatty acids (PUFAs) using this delta-8 desaturase in plants and oleaginous yeast are disclosed.
1. An isolated polynucleotide comprising:
(a) a nucleotide sequence encoding a polypeptide having delta-8 desaturase activity, wherein the polypeptide has at least 80% amino acid identity, based on the Clustal V method of alignment, when compared to an amino acid sequence as set forth in SEQ ID NO:16;
(b) a nucleotide sequence encoding a polypeptide having delta-8 desaturase activity, wherein the nucleotide sequence has at least 80% sequence identity, based on the BLASTN method of alignment, when compared to a nucleotide sequence as set forth in SEQ ID NO:15; or
(c) a complement of the nucleotide sequence of (a) or (b), wherein the complement and the nucleotide sequence consist of the same number of nucleotides and are 100% complementary.
2. The polynucleotide of claim 1 , wherein the amino acid sequence of the polypeptide has at least 85% sequence identity, based on the Clustal V method of alignment, when compared to SEQ ID NO:16.
3. The polynucleotide of claim 1 , wherein the amino acid sequence of the polypeptide has at least 90% sequence identity, based on the Clustal V method of alignment, when compared to SEQ ID NO:16.
4. The polynucleotide of claim 1 , wherein the amino acid sequence of the polypeptide has at least 95% sequence identity, based on the Clustal V method of alignment, when compared to SEQ ID NO:16.
5. The polynucleotide of claim 1 wherein the nucleotide sequence comprises SEQ ID NO:15.
6. The polynucleotide of claim 1 , wherein the amino acid sequence of the polypeptide comprises
(a) SEQ ID NO:16; or
(b) an amino acid sequence that differs from the amino acid sequences in (a) by at least one conservative amino acid substitution.
7. A recombinant DNA construct comprising the polynucleotide of claim 1 , 5 or 6 operably linked to at least one regulatory sequence.
8. A plant cell comprising the recombinant DNA construct of claim 7 .
9. A method for transforming a plant cell, comprising transforming a plant cell with the recombinant construct of claim 7 and selecting those plant cells transformed with the recombinant construct of claim 7 .
10. A method for producing a transformed plant comprising transforming a plant cell with the polynucleotide of claim 1 , 5 or 6 and regenerating a plant from the transformed plant cell.
11. The method of claim 10 wherein the plant is a soybean plant.
12. A seed comprising the recombinant construct of claim 7 .
13. A seed obtained from the plant made by the method of claim 10 , wherein said seed comprises the polynucleotide.
14. A method for making long-chain polyunsaturated fatty acids in a plant cell comprising:
(a) transforming a cell with the recombinant construct of claim 7 ; and
(b) selecting those transformed cells that make long-chain polyunsaturated fatty acids.
15. An oilseed plant comprising the recombinant construct of claim 7 .
16. The oilseed plant of claim 15 , wherein the oilseed plant is selected from the group consisting of soybean, Brassica species, sunflower, maize, cotton, flax and safflower.
17. The oilseed plant of claim 15 , wherein the oilseed plant is selected from the group consisting of soybean, Brassica species, sunflower, maize, cotton, flax, and safflower and further wherein the oilseed plant produces a polyunsaturated fatty acid selected from the group consisting of arachidonic acid, eicosadienoic acid, eicosapentaenoic acid, eicosatetraenoic acid, eicosatrienoic acid, dihomo-gammalinolenic acid, docosapentaenoic acid and docosahexaenoic acid.
18. A seed obtained from the oilseed plant of claim 15 , wherein said seed comprises the recombinant construct.
19. Food or feed comprising the seed of claim 18 .
20. An isolated polynucleotide comprising a nucleotide sequence encoding a polypeptide having delta-8 desaturase activity, wherein the nucleotide sequence has at least 86% sequence identity, based on the BLASTN method of alignment, when compared to a nucleotide sequence as set for the in SEQ ID NO:15.
21. Progeny of the plant of claim 15 , wherein said progeny comprise the recombinant construct.