Use of transgenic mice model for understanding the placentation: towards clinical applications in human obstetrical pathologies ?

The mammalian embryo and fetus are unable to develop without a well-establi shed, functional placenta. This transitory yet indispensable structure atta ches the conceptus to the uterus and establishes the vascular connections n ecessary for nutrient and gaseous exchange between maternal and fetal compa rtments. Genetic targeting strategy allows the generation of mice lacking a specific gene. Such approaches reveal: (i) the high incidence of mutant em bryonic or fetal death in utero, and (ii) the extraembryonic (placental) ca uses of these deaths. Due to the similarities presented between mouse and h uman placenta, we propose to use the potential of mouse targeting experimen ts as a model in order to understand human obstetrical pathologies. In this paper, we first review genes that have been demonstrated to be required in mice for implantation, choriovitelline and chorioallantoic placentation. U sing examples (integrins, homeoboxs, hepatocyte growth factor or epidermal growth factor receptor...) we demonstrate the reality and efficiency of suc h an approach. Other candidate genes (receptor of leukemia inhibitory facto r, Wnt2 or retinoic acid receptor alpha...) in order to understand, prevent and treat human obstetrical pathologies.