The growth arrest specific gene (gas6) protein is expressed in abnormal embryos sired by male golden hamsters with accessory sex glands removed

Expression of growth arrest specific gene (gas6) and its receptors in embry onic and uterine tissues in normal pregnancy and pregnancy that produces ab normal embryos sired by hamsters with partial or total deletion of male acc essory sex glands was studied by in situ hybridization, immunohistochemistr y, reverse-transcription polymerization reaction and enzyme-linked immunoab sorbant assay. At oestrus, very strong gas6 mRNA and Gas6 expression were s een only in the uterine epithelium and endometrial glands. Upon implantatio n, both of them could be demonstrated in the decidualizing stroma. From day 4 to day 7 p.c, gas6 mRNA was present in the embryo, but Gas6 immunoreacti vity was only found in those showing features of degeneration. The gas6:bet a -actin mRNA ratio was low in oestrus and at day 4 of pregnancy but rose a s the embryo grew. As for the receptors, Rse was detected in embryonic cell s during days 5-7 p.c., and decidual cell from days 4 to 7 p.c., but Mer co uld be found in decidual cells and trophoblasts. It was concluded that gas6 had a role in endometrial transformation during decidualization and tropho blastic invasion. In the embryo, gas6 was transcribed, but the protein was only produced in response to need, such as when normal progression of devel opment was threatened.