Modulation of Vitellogenin II Gene by Estradiol and Progesterone in the Japanese Quail

Abstract

Estrogen and progesterone receptors are reported to functionally cooperate in gene activation if their cognate binding sites are close to one another in the gene. Our studies show that the expression of the vitellogenin (VTG) gene is induced by estradiol alone or along with progesterone. Progesterone alone inhibits the expression completely. Methylation status of the VTG gene remains unaltered by steroid hormones. Gel mobility shift assay shows that qualitative and quantitative changes occur in thetrans-acting factor(s) that bind to estradiol and progesterone responsive elements (ERE and PRE) after administration of these steroid hormones. We, therefore, conclude that the interaction oftrans-acting factors that bind to ERE and PRE play a role in the regulation of VTG gene expression.