| 摘要 |
The invention relates to a method for producing unsaturated fatty acids comprising at least two double bonds, and a method for producing triglycerid es having an increased content of polyunsaturated fatty acids comprising at lea st two double bonds. The invention also relates to the advantageous use of the nucleic acid sequences of SEQ ID NO: 1, SEQ ID NO: 3, SEQ ID NO: 5, SEQ ID N O: 9, SEQ ID NO: 11 or SEQ ID NO: 18 in the inventive methods, and for producin g a transgenic organism, preferably a transgenic plant or a transgenic micro- organism having an increased content of fatty acids, oils or lipids containi ng unsaturated C18, C20, or C22 fatty acids. The invention further relates to novel desaturases comprising the sequences of SEQ ID NO. 1, SEQ ID NO: 3, SE Q ID NO: 5 and SEQ ID NO: 11, or the homologues, derivatives or analogues thereof, and gene constructs comprising said genes or the homologues, derivatives or analogues thereof, in addition to the use of the same, either alone or combined with biosynthesis genes of polyunsaturated fatty acids, as advantageously represented in SEQ ID NO: 7 and SEQ ID NO: 9. Furthermore, th e invention relates to isolated nucleic acid sequences, expression cassettes containing said nucleic acid sequences, vectors, and transgenic organisms containing at least one nucleic acid sequence or an expression cassette. The invention also relates to unsaturated fatty acids comprising at least two double bonds and triglycerides having an increased content of unsaturated fatty acids comprising at least two double bonds, and the use of the same. Finally, the invention relates to multi-expression cassettes for seed-specif ic expression, in addition to vectors or organisms comprising a desaturase gene , either alone or combined with other desaturases having the sequence of SEQ I D NO: 7 and/or elongase genes having the sequence of ID NO: 9 or the homologue s, derivatives or analogues of the same, expressed by means of the above- mentioned expression cassettes. |
