Delta-5 Desaturases and method for producing polyunsaturated fatty acids in transgenic non-human organisms

New polynucleotides (A), encoding desaturases and elongases, comprise or are based on eight specific nucleotide sequences obtained from Ostreococcus lucimarinus (a species of algae). New polynucleotides (A) contain a nucleotide sequence selected from (a) sequences designated SEQ ID No. 1, 3, 5, 7, 9, 11, 13 or 15, (b) sequences encoding an aminoacid sequence designated SEQ ID No. 2, 4, 6, 8, 10, 12, 14 or 16, (c) sequences encoding a peptide having at least 80% homology with a peptide encoded by (a) or (b) and showing desaturase or elongase activity and (d) sequences of a fragment of (a), (b) or (c) which encodes a polypeptide showing desaturase or elongase activity. Independent claims are included for: (1) a vector (B) containing (A); (2) host cells containing (A) or (B); (3) the preparation of a polypeptide (C) with desaturase or elongase activity, by expressing (A) in a host cell and recovering (C) (encoded by (A)) from the cell; (4) the polypeptides (C) encoded by (A) or obtained by the above process; (5) antibodies which specifically recognize (C); (6) transgenic, non-human organisms containing (A), (B) or the transformed host cells; (7) the production of polyunsaturated fatty acids (PUFA's) or their derivatives of formula R 1-CO-(CH 2) n-(CH=CH-CH 2) m-(CH 2) p-CH 3 (I), by culturing the host cells or transgenic organisms under appropriate conditions for biosynthesis of (I); and (8) the production of an oil, lipid or fatty acid composition (D), involving formulating an appropriate material (I) obtained by the above process. R 1OH, coenzyme A (thioester), lysophosphatidyl-choline, lysophosphatidyl-ethanolamine, lysophosphatidyl-glycerol, lysodiphosphatidyl-glycerol, lysophosphatidyl-serine, lysophosphatidyl-inositol, sphingo-base or glyceryl residue of formula -OCH 2CH(OR 3)CH 2(OR 3); R 2H, lysophosphatidyl-choline, lysophosphatidyl-ethanolamine, lysophosphatidyl-glycerol, lysodiphosphatidyl-glycerol, lysophosphatidyl-serine, lysophosphatidyl-inositol, optionally unsaturated 2-24C alkylcarbonyl or -CO-(CH 2) n-(CH=CH-CH 2) m-(CH 2) p-CH 3; R 3H, optionally unsaturated 2-24C alkylcarbonyl or -CO-(CH 2) n-(CH=CH-CH 2) m-(CH 2) p-CH 3; n : 2-7 or 9; m : 2-6; p : 0 or 3. ACTIVITY : Cardiant; Cytostatic; Antidiabetic. MECHANISM OF ACTION : None given.