The promoter region associated with the Yarrowia lipolytica glycerol-3-phosphate O-acyltransferase (gpat) gene has been found to be particularly effective for the expression of heterologous genes in oleaginous yeast. The promoter regions of the instant invention have been shown to be suitable to drive high-level expression of genes involved in the production of .omega.-3 and .omega.-6 fatty acids.