Chicken Egg White Genes: Multihormonal Regulation in a Primary Cell Culture System

Abstract

A primary cell culture from estrogen-withdrawn chicken oviduct has been developed in which the genes for the major egg white proteins, ovalbumin and conalbumin, are induced by steroid hormones. The responsiveness of the isolated cells depends on the combination of enzymes employed to dissociate the oviduct; trypsin and pronase are essential. Administration of estradiol to cultured cells is insufficient to induce ovalbumin mRNA (mRNAov) to levels achieved in vivo. Both insulin and a second steroid (a glucocorticoid, progestin, or androgen) are required for the induction of the ovalbumin gene by estradiol to the extent reached in vivo. Although low levels of a progestin or androgen can synergize with estradiol to obtain an induction of mRNAov, we have demonstrated that a physiological concentration of corticosterone (10(-8) M) potentiates a large response to estradiol without causing an induction when added alone. When estradiol, corticosterone, and insulin are present in the culture medium, mRNAov increases from about 20 to 6500 molecules/cell by 55 h. With the same culture conditions, conalbumin mRNA increases from about 120 to 4300 molecules/cell by 52 h. After about 55 h, the level of egg white mRNAs decreases, and this reduction in mRNAov correlates with a diminished transcription of that gene. The data obtained with the cultured cells demonstrate that the induction of the ovalbumin gene requires the permissive effects of insulin and a second steroid (probably a glucocorticoid in vivo) to facilitate the response to estradiol.

Molecular cloning, expression, and regulation of the ovalbumin gene in pigeon oviduct epithelial cells

“…In chicken oviduct epithelial cells, the hormones E 2 , P 4 , and Cort could upregulate OVA mRNA expression (McKnight and Palmiter, 1979). Combination treatment with 10 -7 M E 2 and 10 -8 M Cort upregulated expression in chicken (Sanders and McKnight, 1985). In this study, we also found that E 2 , P 4 , and Cort stimulated pigeon OVA gene expression.…”

“…Several steroid hormones are involved in the regulation of chicken OVA mRNA transcription in the chicken oviduct (McKnight and Palmiter, 1979;Sanders and McKnight, 1985). In the chicken OVA gene, two major regulatory elements at the 5'-flanking region coordinate regulation of the OVA gene: the steroid-dependent regulatory element (SDRE) and the negative regulatory element (NRE).…”

Molecular cloning, expression, and regulation of estrogen receptors in pigeon oviduct epithelial cells

“…Therefore, we conclude that the expression of pigeon ERa can be regulated by 17b-estradiol in a dose-dependent manner. Sanders and McKnight (1985) reported that a combination of progesterone and estrogen treatment expressed more OVA mRNA than an estrogen-only treatment in cultured chicken oviduct cells. Moreover, progesterone was able to repress the expression of ERa (Hsueh et al, 1976;Kraus and Katzenellenbogen, 1993).…”

Chicken Ovalbumin Promoter Is Demethylated upon Expression in the Regions Specifically Involved in Estrogen-Responsiveness

“…Oviduct cells were isolated from the magnum portion of diethylstilbestrol-treated chickens by the method of Sanders and Mcknight, 25) except that diethylstilbestrol dissolved in olive oil was injected intramuscularly at a dose of 1 mg/d. The cells were stained with anti-ovalbumin antibody, and the percentage of ovalbumin-expressing cells was approximately 80-90% (Fig.…”