Fatty acid metabolism in Drosophila melanogaster: Interaction between dietary fatty acids and De novo synthesis

Abstract

1. 1. Larvae of Drosophila melanogaster were reared on medium supplemented with one of five highly purified 16- and 18-carbon dietary fatty acids. Gas chromatographic analyses of the total fatty acid compositions from late third-instar larvae revealed that striking changes took place in the total fatty acid composition in response to these dietary supplements. Dietary linoleate caused the formation of a 14-carbon and a 16-carbon diene which are normally not found in Drosophila. 2. 2. Random- 14C- and 1- 14C-labeled palmitate, stearate and oleate were employed under a variety of dietary conditions and the metabolic fates of these components are discussed. 3. 3. Labeled acetate was incorporated into all saturated and mono-unsaturated fatty acids but was not incorporated into more highly unsaturated components. 4. 4. Random- 14C-long-chained fatty acids and 3H-acetate were employed simultaneously under certain conditions. From this study it was concluded that there probably is more than one pathway in the formation of monoenes. 5. 5. The percentage distribution of label from acetate was relatively constant and independent of the interactions caused by the dietary acids. 6. 6. The interactions which were observed in Drosophila are compared with those which occur in other organisms.