Many environmental pollutants have estrogenic activity in animals. Xenobiotic estrogens include many pesticides and industrial chemicals that biocumulate. The impact of these common pollutants on the reproductive success of wildlife may be considerable, particularly in threatened or endangered species. This research examined the use of plasma vitellogenin in males as a biomarker for estrogenic ...

Vitellogenin (1, 2) is a sex-limited phosphoprotein secreted by the liver in Xenopus females (3, 4) and selectively transferred via the circulatory system to growing oocytes, within which it is converted into the yolk proteins lipovitellin and phosvitin (3, 5, 6) . Selective uptake (7) and conversion (8) of vitellogenin can also take place in isolated oocytes . The available evidence indicates ...

In fish, vitellogenin is an important nutritional precursor protein produced solely in the liver and released into the blood where it binds calcium. In the gilthead sea bream (Sparus auratus) 17beta-Estradiol (E2) plays an important role in the synthesis of vitellogenin, but also the pituitary hormones prolactin (PRL) and growth hormone (GH) can stimulate vitellogenin induction in fish. Conside...

The objective of this study was to investigate the synthesis site of vitellogenin in the Chinese mitten-handed crab, Eriocheir sinensis. Using the RT-PCR techniques, the cDNA fragments isolated from the ovaries of vitellogenic female crab, we found that its deduced amino acid sequence had a high identity with that from other decapods crustacean vitellogenin. This cDNA fragments were used as pro...

Plasma from estrogenized, [32P] NaH2PO4-injected murrel, Channa punctatus was collected in the presence of proteolytic inhibitors and subjected to different separation procedures singly or in combination, viz., gel filtration chromatography on Ultrogel AcA 34, ion-exchange chromatography on DEAE sephacel, or selective precipitation with dimethylformamide or with Mg2+: EDTA in order to isolate v...

-The vitellogenins of Hyalophora cecropia and Blattella germanica have similar Stokes' radii (69 and 75,&), sedimentation coefficients (15.9 and 16.8s) and isoelectric points (pH 5.7 and 5.0), and share similar amino acid compositions with vitellogenins of other animals. The two vitellogenins show no immunological crossreaction. Blattella oocytes take up their own vitellogenin in vivo at a rapi...

In the ant Ectatomma tuberculatum (Olivier 1792), workers have active ovaries and lay trophic eggs that are eaten by the queen and larvae. Vitellogenins are the main proteins found in the eggs of insects and are the source of nutrients for the embryo in the fertilized eggs and for adults in the trophic eggs. In social insects, vitellogenin titres vary between castes and affect reproductive soci...

Vitellogenin (1, 2) is a sex-limited phosphoprotein secreted by the liver in Xenopus females (3, 4) and selectively transferred via the circulatory system to growing oocytes, within which it is converted into the yolk proteins lipovitellin and phosvitin (3, 5, 6) . Selective uptake (7) and conversion (8) of vitellogenin can also take place in isolated oocytes . The available evidence indicates ...

We report initial studies on estrogen-mediated regulation of egg yolk protein synthesis in the rooster. Egg yolk proteins are normally synthesized as a large precursor, vitellogenin, in the liver of the laying hen; roosters synthesize vitellogenin only when treated with estrogen. Polysomal RNA from the liver of estrogen-treated roosters was translated in a reticulocyte cell-free system, and the...