The regulatory sequences (i.e., promoter regions, introns and enhancers) associated with the Yarrowia lipolytica gene encoding fructose bis-phospate aldolase (FBA1) have been found to be particularly effective for the expression of heterologus genes in oleaginous yeast. The promoter regions of the invention have been shown to drive high-level expression of genes involved in the production of .omega.-3 and .omega.-6 fatty acids.