Abstract
The aim of this study was to determine whether estrogen regulates the progesterone receptor mRNA (PRmRNA) expression in the shell gland. The PRmRNA in the shell gland of estradiol-17β(E2)-or its vehicle-treated chicks as well as of laying hens was localized by an in situ hybridization method using digoxigenin-labeled probes. No signal for PRmRNA was observed in the shell gland tunica mucosa consisting of surface epithelium and stroma in vehicle-treated chicks. In the E2-treated chicks, the tubular gland cells contained significant amounts of PRmRNA and the surface epithelium showed very weak signals. No signal for PRmRNA was observed in the tunica mucosa of the shell gland in laying hens. These results suggest that estrogen may be a factor regulating the PRmRNA expression in the shell gland.
