Desaturase genes and uses thereof

A method of producing a desaturase comprising the steps of:

• a) isolating a nucleic acid molecule comprising the nucleotide sequence of SEQ ID NO:28;
• b) constructing a vector comprising:
• i) said isolated nucleotide acid molecule operably linked to ii) a regulatory sequence;
• c) introducing said vector into a host cell for a time and conditions sufficient for expression of said desaturase, wherein said host cell is a prokaryotic or a eukaryotic cell, wherein said eukaryotic cell is selected from the group consisting of an insect cell, a plant cell and a fungal cell.

A method for producing a polyunsaturated fatty acid comprising the steps of:

• a) isolating a nucleic acid molecule comprising the nucleotide sequence of SEQ ID NO:28;
• b) constructing a vector comprising said isolated nucleic acid molecule;
• c) introducing said vector into a host cell for a time and under conditions sufficient for expression of Δ5-desaturase enzyme, wherein said host cell is a prokaryotic cell or a eukaryotic cell, wherein said eukaryotic cell is selected from the group consisting of an insect cell, a plant cell and a fungal cell;
• and
• d) exposing said expressed Δ5-desaturase enzyme to a substrate polyunsaturated fatty acid in order to convert said substrate to a product polyunsaturated fatty acid.