NUCLEIC ACID ENCODING A .DELTA.5-ELONGASE POLYPEPTIDE DERIVED FROM OSTREOCOCCUS TAURI, METHODS AND USES THEREOF

摘要

The invention relates to a method for the production of multiply-unsaturatedfatty acids in an organism, into which nucleic acids have been introduced,which code for polypeptides with .DELTA.-5 elongase activity. Said nucleicacid sequences, optionally with further nucleic acid sequences, coding forpolypeptides for the biosynthesis of fatty acids and lipid metabolism, areadvantageously expressed in the organism. Nucleic acid sequences coding for a.DELTA.-6 desaturase, a .DELTA.-5 desaturase, .DELTA.-4 desaturase and/or.DELTA.-6 elongase activity are particularly advantageous and, advantageously,said saturases and elongases are derived from Thalassiosira, Euglena orOstreococcus. The invention further relates to a method for the production ofoils and/or triacylglycerides with an increased content of long-chain,multiply-unsaturated fatty acids. A particular embodiment of the invention isa method for the production of unsaturated .omega.-3 fatty acids and a methodfor the production of triglycerides with an increased content of unsaturatedfatty acids, in particular, of .DELTA.-3 fatty acids with more than threedouble bonds. Also disclosed is the production of a transgenic organism,preferably a transgenic plant, or a transgenic microorganism with increasedcontent of .omega.-3 fatty acids, oils or lipids with .omega.-3 double bondsas a result of the expression of the elongases and desaturases employed in theabove method, preferably in combination with .omega.-3 desaturases, forexample a .omega.-3 desaturase from fungi of the family Pythiaceae such as thegenus Phytophtora, for example, the genus and species Phytophtora infestans,or a .omega.-3 desaturase from algae such as the family Prasinophyceae, forexample, the genus Ostreococcus and, particularly, the genus and speciesOstreococcus tauri or diatomaceae such as the genus Thalassiosira and,particularly, the genus and species Thalassiosira pseudonana. The inventionalso relates to the nucleic acid sequences, nucleic acid constructs, vectorsand organisms containing the nucleic acid sequences and/or the nucleic acidconstructs and transgenic organisms containing said nucleic acid sequences,nucleic acid constructs and/or vectors. A further part of the inventionrelates to oils, lipids and/or fatty acids produced according to the abovemethod and use thereof and, furthermore, unsaturated fatty acids andtriglycerides with an increased content of unsaturated fatty acids and usethereof.