Investigations of the capacity of synthesizing 3β-sterols in mollusca—XIV. Biosynthesis and composition of sterols in some bivalves (Eulamellibranchia)

Abstract

1. 1. The incorporation of sodium acetate-1- or -2- 14C or dl-mevalonate-2- 14C into some lipid classes of the eulamellibranchian bivalves Anodonta cygnea, Cardium edule, Cyprina islandica and Mya arenaria was investigated. 2. 2. It was demonstrated that the animals were able to synthesize both saponifiable and non-saponifiable lipids. The presence of squalene could not be shown, however. 3. 3. Sterols were non-radioactive after the administration of mevalonate or acetate-1- 14C, but some radioactivity was present in the sterols after the injection of sodium acetate-1- 14C when incubations had lasted for 120 hr. 4. 4. Sterols were radioactive after the injection of sodium acetate-2- 14C. These results are discussed. 5. 5. Fifty per cent or more of the radioactivity in the sterols was present in sterols with more than twenty-seven carbon atoms. 6. 6. It was concluded that the eulamellibranchian bivalves are able to synthesize C 27 sterols and to alkylate these sterols to C 28 and C 29 ones. 7. 7. The sterol composition of the animals was determined and was compared with that of the anisomyarian bivalves.