MODULATION OF VITELLOGENIN-II GENE BY ESTRADIOL AND PROGESTERONE IN THE JAPANESE-QUAIL

Estrogen and progesterone receptors are reported to functionally coope rate in gene activation if their cognate binding sites are close to on e another in the gene. Our studies show that the expression oi the vit ellogenin (VTG) gene is induced by estradiol alone or along with proge sterone. Progesterone alone inhibits the expression completely. Methyl ation status of the VTG gene remains unaltered by steroid hormones. Ge l mobility shift assay shows that qualitative and quantitative changes occur in the trans-acting factor(s) that bind to estradiol and proges terone responsive elements (ERE and PRE) after administration of these steroid hormones. We, therefore, conclude that the interaction of tra ns-acting factors that bind to ERE and PRE play a role in the regulati on of VTG gene expression. (C) 1996 Academic Press, Inc.