title: Implantation and the placenta: key pieces of the development puzzle.
abstract: The mammalian embryo cannot develop without the placenta. Its specialized cells (trophoblast, endoderm, and extraembryonic mesoderm) form early in development. They attach the embryo to the uterus (implantation) and form vascular connections necessary for nutrient transport. In addition, the placenta redirects maternal endocrine, immune, and metabolic functions to the embryo's advantage. These complex activities are sensitive to disruption, as shown by the high incidence of early embryonic mortality and pregnancy diseases in humans, as well as the numerous peri-implantation lethal mutations in mice. Integration of molecular and developmental approaches has recently produced insights into the molecules that control these processes.
authors.affiliation: Samuel Lunenfeld Research Institute, Mount Sinai Hospital, Toronto, Ontario, Canada.
authors.forename: J C
authors.initials: JC
authors.lastname: Cross
authors.forename: Z
authors.initials: Z
authors.lastname: Werb
authors.forename: S J
authors.initials: SJ
authors.lastname: Fisher
mesh_terms: D000818:Animals; D001755:Blastocyst / Q000502:physiology; D002454:Cell Differentiation; D010064:Embryo Implantation / Q000502:physiology*; D005314:Embryonic and Fetal Development / Q000235:genetics / Q000502:physiology*; D005260:Female; D018507:Gene Expression Regulation, Developmental; D006728:Hormones / Q000502:physiology; D006801:Humans; D007108:Immune Tolerance; D008297:Male; D010920:Placenta / Q000166:cytology / Q000502:physiology*; D014327:Trophoblasts / Q000502:physiology; D014599:Uterus / Q000502:physiology
chemical_list: D006728:Hormones