title: Studies on sex-organ development. Prenatal effect of oestrogenic hormone on tubular-gland cell morphogenesis and ovalbumin-gene expression in the chick Müllerian duct.
abstract: The effects of diethylstilboestrol on morphogenesis and cyto-differentiation of the chick-embryo left Müllerian duct were examined. Embryos were treated at different stages of development with maximal-responsive doses of diethylstilboestrol over a 5-day interval. The shell gland and magnum regions of the Müllerian duct were then assayed for growth and histological morphogenesis. The results were correlated with diethylstilboestrol-induced ovalbumin-gene expression as measured by ovalbumin-mRNA (mRNAov) accumulation and the relative rate of ovalbumin synthesis. Treatment of the embryo from day 10 to day 15 of incubation induces morphogenesis of tubular-gland cells in the Müllerian-duct magnum. Although these cells constitute 10% of the total cell population and contain an average of 8000 molecules of mRNAov per cell, ovalbumin synthesis is only 0.85% of total magnum protein synthesis. The Müllerian-duct magnum of embryos treated from day 13 to day 18 of incubation contains about 30% tubular-gland cells, which have accumulated an average of 7000 molecules of mRNAov per cell, but ovalbumin synthesis is only 3.25% of total magnum protein synthesis. The Müllerian-duct magnum of embryos treated from day 16 to day 21 of incubation contains about 50% tubular-gland cells, which have accumulated an average of 6500 mRNAov molecules per cell, and ovalbumin synthesis is 10% of total magnum protein synthesis. Oestrogen responsiveness develops simultaneously in the Müllerian-duct magnum and shell-gland regions. Compared with the rate of diethylstilboestrol-induced oviduct growth, the relative rate of diethylstilboestrol-induced Müllerian-duct growth increases with embryonic age, from 20-fold lower in the 10-day embryo to only 3-fold lower in the 16-day embryo. All results are discussed in comparison with the responses to oestrogen of the immature chick oviduct, and in terms of the ontogeny of hormone-competent epithelial and stromal components of the Müllerian duct. It is concluded that the development of oestrogenic competence in the embryonic Müllerian duct is a multiphasic phenomenon. A dramatic increase in hormone responsiveness in the Müllerian duct occurs between days 10 and 16 of development, and a less dramatic final maturation of oestrogen responsiveness occurs between day 16 of development and 1 week after hatching.
mesh_terms: D000375:Aging; D000818:Animals; D002454:Cell Differentiation / Q000187:drug effects; D002642:Chick Embryo; D004247:DNA / Q000378:metabolism; D004054:Diethylstilbestrol / Q000494:pharmacology*; D009024:Morphogenesis / Q000187:drug effects; D009095:Mullerian Ducts / Q000166:cytology / Q000187:drug effects / Q000378:metabolism* / Q000502:physiology; D009693:Nucleic Acid Hybridization; D010047:Ovalbumin / Q000096:biosynthesis / Q000235:genetics*; D014176:Protein Biosynthesis / Q000187:drug effects; D012313:RNA / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism
chemical_list: D012333:RNA, Messenger; D012313:RNA; D004054:Diethylstilbestrol; D010047:Ovalbumin; D004247:DNA