Effect of Exogenously Administered Methyl Farnesoate and 20-OH Ecdysone on Polypeptide Profile of Vitellogenin and Vitellin in the Freshwater Crab Travancoriana schirnerae

Abstract

| This study evaluated the effects of exogenously administered methyl farnesoate (MF) and 20-OH ecdysone (20E) on polypeptide profile of circulating vitellogenin (Vg) and ovarian vitellin (Vn) in the edible freshwater crab Travancoriana schirnerae by sodium dodecyl sulphate-polyacrylamide gel electrophoresis. The results indicated that the polypeptide profiles of yolk proteins in the hemolymph and ovary of control and experimental females varied with the stage of development of the ovary. Our observations also revealed that both MF and 20E administration was able to induce the production of Vg and Vn during the avitellogenic and previtellogenic phases manifested by the presence of Vg and Vn polypeptide subunits in the electropherograms of experimentals over the controls. Moreover, the electropherograms of MF and 20E crabs during the vitellogenic phase displayed more number of Vg and Vn subunits with increased staining intensity and thickness compared to the control crabs. It was concluded that though both MF and 20E were able to induce or enhance the production of Vg and Vn during the avitellogenic, previtellogenic and vitellogenic phases, the effects were far more pronounced in MF injected females than the 20E injected crabs.