Delta 6 desaturases from primulaceae, expressing plants and pufa-containing oils

• US 20050089865A1
• Filed: 02/06/2003
• Published: 04/28/2005
• Est. Priority Date: 02/27/2002
• Status: Active Grant

• Current Assignee: Iacr-Rothamsted
• Original Assignee: Iacr-Rothamsted
• Inventors: Sayanova, Olga, Napier, Johnathan A
• Granted Patent: US 7,554,008 B2
• Time in Patent Office: Days
• US Class Current: 435/6
• CPC Class Codes: A61P 3/00 Drugs for disorders of the metabolism of the blood or the extracellular fluid A61P7/00
• CPC Class Codes: C12N 15/8247 involving modified lipid metabolism, e.g. seed oil composition
• CPC Class Codes: C12N 9/0083 Miscellaneous (1.14.99)
• CPC Class Codes: C12P 7/6427 Polyunsaturated fatty acids [PUFA], i.e. having two or more double bonds in their backbone
• CPC Class Codes: C12P 7/6432 Eicosapentaenoic acids [EPA]
• CPC Class Codes: C12P 7/6434 Docosahexenoic acids [DHA]
• CPC Class Codes: C12P 7/6472 containing polyunsaturated fatty acid [PUFA] residues, i.e. having two or more double bonds in their backbone

Abstract

The present invention relates to an improved method for the specific production of unsaturated ω-3 fatty acids and a method for the production of triglycerides having an increased content of unsaturated fatty acids, in particular ω-3 fatty acids having more than three double bonds. The invention relates to the production of a transgenic organism, preferably a transgenic plant or a transgenic microorganism, having an increased content of fatty acids, oils or lipids having Δ 6 double bonds due to the expression of a Δ 6-desaturase from Primulaceae. The invention additionally relates to expression cassettes containing a nucleic acid sequence, a vector and organisms containing at least one nucleic acid sequence or an expression cassette. The invention further relates to unsaturated fatty acids and triglycerides having an increased content of unsaturated fatty acids and use thereof.

Claims

1. An isolated nucleic acid sequences which sequence that encodes a polypeptide having Δ

6-desaturase activity, wherein the Δ

6-desaturase activity exhibits higher activity for ω

-3 fatty acids as compared to ω

-6 fatty acids.

2. The isolated nucleic acid sequence of claim 1, wherein said sequence is selected from the group consisting of:

a) a the nucleic acid sequence of SEQ ID NO;

1 or SEQ ID NO;

3;

b) nucleic acid sequences derived as a result of the degenerate genetic code from the amino acid sequence encoded in SEQ ID NO;

1 or SEQ ID NO;

3;

c) derivatives of the nucleic acid sequence of SEQ ID NO;

1 or SEQ ID NO;

3, which encode a polypeptide that contains the amino acid sequence of SEQ ID NO;

2 or SEQ ID NO;

4, has at least 75% amino acid homology with SEQ ID NO;

2 or SEQ ID NO;

4, and possesses a Δ

6-desaturase activity.

3. The isolated nucleic acid sequence of claim 1, wherein said sequence is derived from a plant.

4. The isolated nucleic acid sequence of claim 1, wherein said sequence is derived from the genera Muscariodides or Aleuritia.

5. An amino acid sequence which is encoded by an the isolated nucleic acid sequence of claim 1.

6. A gene construct containing the isolated nucleic acid sequence of claim 1, wherein said nucleic acid sequence is functionally linked to one or more regulation signals.

7. A vector containing the nucleic acid sequence of claim 1.

8. A transgenic nonhuman organism containing the nucleic acid sequence of claim 1.

9. The transgenic nonhuman organism of claim 8, wherein said organism is a microorganism, an animal or a plant.

10. The transgenic nonhuman organism of claim 8, wherein said organism is a plant.

11. A method for producing polyunsaturated fatty acids, wherein the method comprises growing a transgenic organism which comprises the nucleic acid sequence of claim 1, wherein, due to the activity of said Δ

-6 desaturase, polyunsaturated fatty acids are formed in said organism which exhibit an increased content of ω

-3 fatty acids.

12. The method of claim 11, wherein in the stearidonic acid, eicosapentaenoic acid or docosahexaenoic acid are produced.

13. The method of claim 11, further comprising isolating polyunsaturated fatty acid molecules from said organism in the form of an oil, lipid or a free fatty acid.

14. The method of claim 11, wherein said organism is a microorganism, a nonhuman animal or a plant.

15. The method of claim 11, wherein said organism is a transgenic plant.

16. The method of claim 13, wherein said polyunsaturated fatty acid molecules comprise a C₁₈ fatty acid having at least three double bonds.

17. Oil, lipids or fatty acids, or a fraction thereof, produced by the method of claim 11.

18. A composition comprising the oil, lipids or fatty acids, or faction thereof, of claim 17, further comprising polyunsaturated fatty acids.

19. Animal feed, foodstuffs, cosmetics or pharmaceuticals comprising the oil, lipids or fatty acids, or fraction thereof, of claim 17.

20. The isolated nucleic acid of claim 1, wherein the Δ

6-desaturase activity toward ω

-3 fatty acids as compared to ω

-6 fatty acids is higher by a factor of at least 1.5.

21. The isolated nucleic acid of claim 20, wherein the factor is at least 3.

22. The isolated nucleic acid of claim 20, wherein the factor is at least 5.

23. A vector containing the gene construct of claim 6.

24. A transgenic nonhuman organism containing the gene construct of claim 6.

25. The gene construct of claim 6, wherein the one or more regulation signals comprise one or more promoters, terminators, or polyadenylation sites.

26. The method of claim 11, which produces triglycerides having an increased content of saturated or unsaturated fatty acids.

27. The method of claim 11, wherein said organism has an increased content of polyunsaturated fatty acids as compared a similar organism without said nucleic acid.

28. The method of claim 27, wherein said increased content of polyunsaturated fatty acids is at least 10% increased as compared the similar organism.

29. The method of claim 27, wherein said increased content of polyunsaturated fatty acids is at least 20% increased as compared the similar organism.

30. The method of claim 27, wherein said increased content of polyunsaturated fatty acids is at least 40% increased as compared the similar organism.

31. The method of claim 13, wherein said polyunsaturated fatty acid molecules comprise fatty acids having an increased content of Δ

6-double bonds.