Immunocytochemical Identification of the Site of Vitellogenin Synthesis in the Freshwater Prawn Macrobrachium nipponense

Abstract

The site of vitellogenin synthesis in the freshwater prawn Macrobrachium nipponense was examined immunocytochemically using antibodies raised against lipovitellin purified from mature M. nipponense ovaries. The molecular weight of purified lipovitellin was estimated to be 350 kDa by gel filtration. The antiserum cross-reacted with vitellogenin in the hemolymph of the mature female prawn, and could therefore be used to demonstrate the possible site of vitellogenin synthesis immunocytochemically employing the peroxidase-anti-peroxidase (PAP) reaction. Hepatopancreas, sub-epidermal tissue, muscle, and ovary were fixed with periodate-lysine paraformaldehyde solution after which paraffin sections were made. In mature females, oocytes at the yolk globule stage, the hepatopancreas and the sub-epidermal tissue of the lateral somites showed positive PAP reactions. However, the sub-epidermal tissue of the ventral somites, follicular cells of the ovary and muscles did not. No positive reaction was observed in males and immature females. These results suggest that vitellogenin is synthesized in the hepatopancreas and at the sub-epidermal tissue in females at the exogenous vitellogenesis stage. © 1994, The Japanese Society of Fisheries Science. All rights reserved.