In the liver of rainbow trout (Salmo gairdnerii ), vitellogenin (Vg) synthesis is influenced by oestradiol (E sub(2)) which is believed to act through the classical mechanism of steroid hormone action. After binding of the hormone to a soluble specific receptor protein, the oestradiol-receptor complex is translocated to the nucleus, where it interacts with DNA and modulates expression of Vg genes, leading to increased synthesis of specific mRNA and Vg. The authors show here: (i) the presence of specific oestrogen receptors in the cytosol of the male trout liver. (ii) The male liver, offering, an ideal experimental control of "zero" background, the authors followed - in the liver of male trouts - the kinetics of induction of Vg mRNA by hybridization with Vg... |