Development of an anti-vitellin ELISA for the assessment of reproduction in the ridgeback shrimp, Sicyonia ingentis.

To investigate the reproductive regulation of the ridgeback shrimp, Sicyonia ingentis, vitellin (Vn) synthesis was studied. Using gel filtration chromatography and sodium dodecyl sulfate-polyacrylamide gel electrophoresis, Vn was found to have a molecular mass of 322 kDa and to be composed of three subunits of 182, 91 and 85 kDa. Purified Vn was used to prepare anti-Vn antiserum, which was used to develop an enzyme-linked immunosorbent assay (ELISA) with a dynamic range of 0.3-300 ng. The ELISA was used to measure hemolymph levels of yolk proteins. The mean hemolymph concentrations in fresh caught animals ranged from 256 (+/-36.6 S.E.M.) to 1073 (+/-87.6 S.E.M.) mg/ml in stage 2 and 4 animals, respectively. The ELISA was also used to determine the effects of steroid hormone injections in adult non-reproductive female shrimp. One milligram injections of progesterone, 17alpha-hydroxyprogesterone or 17beta-estradiol were administered for three consecutive days to individual females. There were no changes in hemolymph vitellogenin levels during the successive 7-day period following the first injection of any steroid.