Isolated nucleic acid and amino acid sequences encoding a diacylglycerol acyltransferase 2 (DGAT2) polypeptide are provided. Vectors and transgenic cells that include a nucleic acid sequence encoding a DGAT2 polypeptide are also described. Further provided are methods of producing an epoxy fatty acid by transforming a cell with a first isolated nucleic acid that encodes a diacylglycerol acyltransferase polypeptide and a second isolated nucleic acid that encodes an epoxygenase polypeptide, such that expression of the diacylglycerol acyltransferase polypeptide and the epoxygenase polypeptide increases an amount of epoxy fatty acid in the cell.