Hormonal Control of Egg White Protein Messenger RNA Synthesis in the Chicken Oviduct

The chick oviduct is an attractive system for studying the control of specific protein synthesis by steroid hormones (Palmiter 1975; Rosen and O'Malley 1975; Schimke et al. 1975). Readministration of estrogens to estradiol-stimulated and subsequently withdrawn chickens leads to the synthesis of the major egg white proteins ovalbumin, ovomucoid, conalbumin, and lysozyme in the tubular gland cells. These four proteins account for approximately 75% of total protein synthesis in the fully induced oviduct. They are, however, synthesized at different rates: ovalbumin comprises about 50–60% of the cell protein synthesized, conalbumin accounts for about 10%, ovomucoid for about 8%, and lysozyme for 2–3% (Palmiter 1972). The common control, yet the different extent of their accumulation, makes the coordinated synthesis of these proteins attractive for the study of differential gene expression.