Synthesis of long-chain polyunsaturated fatty acids by recombinant cell

A process for producing oil containing eicosapentaenoic acid and docosapentaenoic acid, comprising the steps of obtaining a transgenic seed of an oilseed plant which comprises eicosapentaenoic acid and docosapentaenoic acid in an esterified form as part of triglycerides, and a microalgal fatty acid desaturase, wherein the total fatty acid of the transgenic seed comprises at least 2.5% ω3 C20 fatty acids (w/w) and wherein the docosapentaenoic acid is present at a level based on a conversion ratio of eicosapentaenoic acid to docosapentaenoic acid of at least 5% (w/w), and extracting oil from the transgenic seed so as to thereby produce the oil.