Lipid metabolism in the parasitic and free-living flatworms, Schistosoma mansoni and Dugesia dorotocephala

Abstract

As part of an investigation of lipid metabolism in platyhelminths, the composition and biosynthesis of fatty acids and complex lipids were examined in the parasitic blood fluke Schistosoma mansoni and the free-living planarian Dugesia dorotocephala. Both flatworms have similar lipid patterns, although some quantitative differences exist. Cholesterol, triglyceride, phosphatidylcholine, phosphatidylethanolamine, and phosphatidylinositol constitute their major lipids. D. dorotocephala contains, in addition, ethanolamine plasmalogen and a small amount of cerebroside. The principal fatty acids of the two flatworms are saturated, mono- and polyenoic acids of 16-20-carbon chain lengths. Both the free-living as well as the parasitic flatworms have lost the ability to synthesize de novo sterols and fatty acids. But when supplied with dietary sources, they have the capacity to synthesize all of their complex lipids. © 1970.