Vitellogenesis in the crayfish Rhynchocinetes typus: role of hepatopancreas in lipid yolk biosynthesis.

Biochemical studies in lipid composition of yolk granules from the crayfish Rhynchocinetes typus is shown to be composed mainly of cholesterol and phospholipids. Thin layer chromatography analysis demonstrates phosphatidyl-choline, -ethanolamine and -serine as its major phospholipidic components. In vivo labeling experiments using 32P-orthophosphoric acid suggest that two of the major yolk phospholipid components, phosphatidyl -choline and -serine could be synthesized in the hepatopancreas and subsequently transported via hemolymph to the growing oocyte.