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.