The present invention relates to a &Dgr;5 desaturase, which has the ability to convert dihomo-γ-linolenic acid (DGLA; 20:3 ω-6) to arachidonic acid (ARA; 20:4 ω-6) and/or eicosatetraenoic acid (ETA; 20:4 ω-3) to eicosapentaenoic acid (EPA; 20:5 ω-3). Isolated nucleic acid fragments and recombinant constructs comprising such fragments encoding &Dgr;5 desaturase along with a method of making long chain polyunsaturated fatty acids (PUFAs) using this &Dgr;5 desaturase in oleaginous yeast are disclosed.