Effect of Estrogen on Gene Expression in the Chick Oviduct. Regulation of the Ovomucoid Gene
Journal
Biochemistry
Journal Volume
17
Journal Issue
26
Pages
5773-5780
Date Issued
1978
Author(s)
Abstract
A restriction endonuclease (HhaI) fragment was obtained from a cDNA clone of ovomucoid, pOM100, which contains approximately 650 base pairs of ovomucoid mRNA (mRNAom) sequence. This Hhal fragment was radioactively labeled to high specific activity by nick translation. A single-stranded ovomucoid specific hybridization probe was prepared from the labeled fragments and then used to study the regulation of transcription of the ovomucoid gene by estrogen. About 1900 copies of the ovomucoid mRNA sequences were found in each tubular gland cell nucleus of the chick oviduct after 14 days of diethylstilbestrol treatment. Only very low levels of ovomucoid mRNA sequences were detected in nuclear RNA isolated from chick liver or chick spleen tissues. After 14 days of withdrawal of diethylstilbestrol from the chick, the concentration of ovomucoid mRNA in the chick oviduct decreased to 3 molecules per tubular gland cell nucleus. Read-ministration of a single dose of diethylstilbestrol to these chicks resulted in a gradual increase in the concentration of mRNAom within the first 4 h (from 3 to 38 molecules per tubular gland cell nucleus). By 16 h, the nuclear concentration of mRNAom was 120 molecules per tubular gland cell nucleus. However, with a second injection of estrogen at 48 h, the amount of mRNAom sharply increased to a level (620 molecules/tubular gland cell nucleus) approximately one-third of that observed for chicks stimulated chronically with estrogen. In vitro synthesis of ovomucoid mRNA in isolated nuclei was measured by hybridization to nitrocellulose filters containing cloned ovomucoid DNA and compared with the synthesis of ovalbumin mRNA under the same conditions. In oviduct nuclei isolated from chronically stimulated chicks, the in vitro accumulation of the nascent ovomucoid mRNA transcripts on a molar basis was twofold slower than that determined for ovalbumin mRNA sequences. © 1978, American Chemical Society. All rights reserved.
SDGs
Type
journal article