Producing polyunsaturated fatty acids (I) comprises introducing nucleic acid sequences coding for delta 9 elongase or delta 6 desaturase, delta 8 desaturase or delta 6 elongase, delta 5 desaturase, delta 5 elongase and delta 4 desaturase activity into an organism to produce a transgenic organism whose total lipids include at least 1 wt.% (I). Producing polyunsaturated fatty acids of formula (I) comprises introducing nucleic acid sequences coding for delta 9 elongase or delta 6 desaturase, delta 8 desaturase or delta 6 elongase, delta 5 desaturase, delta 5 elongase and delta 4 desaturase activity into an organism to produce a transgenic organism whose total lipids include at least 1 wt.% of formula (I). [Image] R 1>OH, coenzyme A (thioester), lysophosphatidyl choline, lysophosphatidyl ethanolamine, lysophosphatidyl glycerol, lysophosphatidyl serine, lysophosphatidyl inositol, sphingobase or OCH 2CH(OR 3>)CH 2OR 2>; R 2>H, lysophosphatidyl choline, lysophosphatidyl ethanolamine, lysophosphatidyl glycerol, lysop
