A negative regulating protein (MDBP-2) from rooster liver nuclear extracts binds preferentially to a methylated promoter region 5'TTCACCTTmCGCTATGAGGGGGATCATACTGG3' of the avian vitellogenin II gene (Nucleic Acids Res. 19, 1029-1034, 1991). Treatment of adult and immature roosters with estradiol results in a 90% decrease in the binding activity of MDBP-2 within three days. This corresponds to t...

This study focused on hepatosomatic and gonadosomatic index and levels of plasma 17β-estradiol (E2), vitellogenin (Vtg) and total protein and determined the localization of Vtg in the liver during vitellogenesis in female Chalcalburnus tarichi, an endemic cyprinid species living in the Lake Van, Turkey. The levels of plasma E2, Vtg and total protein in female fish increased during vitellogenesi...

Gene and genome duplications are considered to be the main evolutionary mechanisms contributing to the unrivalled biodiversity of bony fish. New studies of vitellogenin yolk proteins, including a report in BMC Evolutionary Biology, reveal that the genes underlying key evolutionary innovations and adaptations have undergone complex patterns of duplication and functional evolution.

The red swamp crayfish Procambarus clarkii is a highly adaptable, tolerant, and fecund freshwater crayfish that inhabits a wide range of aquatic environments. It is an important crustacean model organism that is used in many research fields, including animal behavior, environmental stress and toxicity, and studies of viral infection. Despite its widespread use, knowledge of the crayfish genome ...

Female reproductive processes, which comprise, amongst others, the synthesis of yolk proteins and the endocrine mechanisms which regulate this synthesis, need a considerable amount of energy and resources. The role of communicating that the required nutritional status has been attained is carried out by nutritional signalling pathways and, in particular, by the insulin receptor (InR) pathway. I...

Disruption in gonadal development of wild roach living in U.K. rivers receiving large volumes of treated sewage effluent is manifest in a variety of ways, ranging from malformation of the germ cells and/or reproductive ducts to altered gamete production. Intersex fish were also found to have an altered endocrine status and an elevated concentration of plasma vitellogenin. Gonadal growth was inh...