Abstract：In this study, we detected gene expressions of Wnts and their related molecules in ectoplacental cone (EPC) from 8-day p.c. pregnant mouse(Mus musculus) uterus based on RT-PCR. The localizations of β-catenin (the key molecule of canonical Wnt pathway) and Dkk1 (an inhibitor of Wnt pathway) were determined by immunofluorescence in EPC. We also primarily studied the function of canonical Wnt pathway during the trophoblast invasion by EPC outgrowth in vitro. Our results showed that 11 of 19 Wnt molecule members, 10 Frizzled receptors, 5 sFRP members ( inhibitors of Wnt pathway), Dkk and kremen1/2 were all expressed in mouse EPC. The β-catenin had strong expression in nucleus of trophoblast cells which were derived from the cultured EPC fraction. The outgrowth diameter of trophoblast increased after treatment of Dkk1, suggesting that the canonical Wnt pathway possibly inhibits the trophoblast invasion. Our study provided a theoretical basis for revealing the role of Wnt signaling pathway in the process of trophoblast invasion during murine placentation.
