The Female-specific Protein (Vitellogenic Protein) in Crustacea with Particular Reference toOrchestic gammarella(Amphipoda)

Abstract

Comparative electrophoretic studies of male and female hemolymph in Crustacea have led to the discovery of a lipoglycoprotein fraction present in females and absent from males. The female-specific protein fraction also contains a pigment which has been identified in a small number of species and appears to be a carotenoid. Further observations indicated that the presence of this fraction is coincident with the presence of maturing ovocytes in the ovary. The major protein component of the vitellus is also a lipoglycocarotenoprotein complex. Comparative analyses have shown that the female-specific protein fraction present in hemolymph and the major protein component of the vitellus are electrophoretically and immunochemically identical. Moreover, in the Amphipod Orchestia gammarella both components appear to have the same molecular weight, estimated as approximately 3 × 105 by Sephadex G 200 gel filtration. Although there is ample evidence to support the idea that the female-specific protein is synthesized externally to the ovary, the site of synthesis still remains unknown. Experimentally induced sex reversal in O. gammarella indicates that the synthesis of the female specific protein is under ovarian control.