Delta-8 desaturases and their use in making polyunsaturated fatty acids
Isolated nucleic acid fragments and recombinant constructs comprising such fragments encoding delta-8 desaturases along with a method of making long-chain polyunsaturated fatty acids (PUFAs) using these delta-8 desaturases in plants and oleaginous yeast.
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:47, SEQ ID NO:49 or SEQ ID NO:57;
(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:92, SEQ ID NO:93 or SEQ ID NO:62;
(c) a nucleotide sequence encoding a polypeptide having delta-8 desaturase activity, wherein the nucleotide sequence hybridizes under stringent conditions to a nucleotide sequence as set forth in SEQ ID NO:92, SEQ ID NO:93 or SEQ ID NO:62; or
(d) a complement of the nucleotide sequence of (a), (b) or (c), 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 nucleotide sequence comprises SEQ ID NO:92, SEQ ID NO:93 or SEQ ID NO:62.
3. The polynucleotide of claim 1 , wherein the amino acid sequence of the polypeptide comprises:
(a) SEQ ID NO:47, SEQ ID NO:49 or SEQ ID NO:57; or
(b) an amino acid sequence that differs from the amino acid sequences in (a) by at least one conservative amino acid substitution.
4. A recombinant DNA construct comprising the polynucleotide of claim 1 operably linked to at least one regulatory sequence.
5. A cell comprising in its genome the recombinant DNA construct of claim 4 .
6. An oilseed plant comprising in its genome the recombinant construct of claim 4 .
7. A transgenic seed comprising in its genome the recombinant construct of claim 4 .
8. Progeny plants obtained from the seed of claim 7 .
9. A method for producing a transformed plant comprising transforming a plant cell with the polynucleotide of claim 1 and regenerating a plant from the transformed plant cell.
10. A transgenic seed obtained from the plant made by the method of claim 9 .
11. Progeny plants obtained from seed of claim 10 .
12. The oilseed plant of claim 6 further comprising
at least one additional recombinant DNA construct comprising an isolated polynucleotide, operably linked to at least one regulatory sequence, encoding a polypeptide selected from the group consisting of a delta-4 desaturase, a delta-5 desaturase, a delta-6 desaturase, a delta-8 desaturase, a delta-12 desaturase, a delta-15 desaturase, a delta-17 desaturase, a delta-9 desaturase, a delta-9 elongase, a C 14/16 elongase, a C 16/18 elongase, a C 18/20 elongase and a C 20/22 elongase.
13. A transgenic seed obtained from the oilseed plant of claim 12 .
14. Progeny plants obtained from the seed of claim 13 .
15. The polynucleotide of claim 1 wherein the nucleotide sequence has at least 90% sequence identity, based on the BLASTN method of alignment, when compared to a nucleotide sequence as set forth in SEQ ID NO:92, SEQ ID NO:93 or SEQ ID NO:62.
16. The cell of claim 5 wherein wherein the nucleotide sequence has at least 90% sequence identity, based on the BLASTN method of alignment, when compared to a nucleotide sequence as set forth in SEQ ID NO:92, SEQ ID NO:93 or SEQ ID NO:62.
17. The oilseed plant of claim 6 wherein the nucleotide sequence has at least 90% sequence identity, based on the BLASTN method of alignment, when compared to a nucleotide sequence as set forth in SEQ ID NO:92, SEQ ID NO:93 or SEQ ID NO:62.
18. The transgenic seed of claim 7 wherein the nucleotide sequence has at least 90% sequence identity, based on the BLASTN method of alignment, when compared to a nucleotide sequence as set forth in SEQ ID NO:92, SEQ ID NO:93 or SEQ ID NO:62.
19. The method of claim 9 wherein the nucleotide sequence has at least 90% sequence identity, based on the BLASTN method of alignment, when compared to a nucleotide sequence as set forth in SEQ ID NO:92, SEQ ID NO:93 or SEQ ID NO:62.
20. The oilseed plant of claim 12 wherein the nucleotide sequence has at least 90% sequence identity, based on the BLASTN method of alignment, when compared to a nucleotide sequence as set forth in SEQ ID NO:92, SEQ ID NO:93 or SEQ ID NO:62.