title: Plasma levels of vitellogenin in Chrysemys picta during the annual gonadal cycle: measurement by specific radioimmunoassay.
abstract: A RIA for turtle (Chrysemys picta) vitellogenin is described. After dimethylformamide precipitation of vitellogenin from the plasma of estrogen-treated female turtles, antibodies were developed in rabbits. The dimethylformamide precipitate was further purified by o-triethylaminoethyl cellulose column chromatography; the vitellogenin component eluted as a single peak. This material was used for iodination by a mild chloramine method. Antibodies to turtle vitellogenin did not cross-react with plasma from male turtles or vitellogenic females of other vertebrate groups, including lizards and snakes. Limited cross-reactivity exists among the chelonians, however. Using a 1:5000 dilution of antiserum, the limit of detection was 15 ng, and the midrange was 320 +/- 45 ng. For an antiserum dilution of 1:1000, these figures were 30 and 600 +/- 37 ng, respectively. Using this assay, the seasonal pattern of plasma vitellogenin in the turtle has been described, and preliminary studies on in vitro hepatic vitellogenesis have been performed.
mesh_terms: D000818:Animals; D003429:Cross Reactions; D004958:Estradiol / Q000494:pharmacology*; D005260:Female; D005399:Fishes; D005779:Immunodiffusion; D007457:Iodine Radioisotopes; D007553:Isotope Labeling / Q000379:methods; D008074:Lipoproteins / Q000097:blood*; D008099:Liver / Q000032:analysis; D011863:Radioimmunoassay / Q000379:methods; D012621:Seasons; D013045:Species Specificity; D014426:Turtles; D014819:Vitellogenins / Q000032:analysis / Q000097:blood*
chemical_list: D007457:Iodine Radioisotopes; D008074:Lipoproteins; D014819:Vitellogenins; D004958:Estradiol