The murine allantois

This chapter focuses on the development of the mouse allantois. The murine allantois is the future umbilical component of the chorioallantoic placenta. Its primary function is to fuse with the chorion and vascularize, thereby serving as the vital connection between mother and fetus for the interchange of nutrients, gases, and metabolic wastes during much of mammalian gestation. Whereas, much effort has been devoted to investigating the role of the mature placenta, studies of the development of its component structures, the chorion and the allantois, have been minimal. In the development of any vertebrate embryo, only part of the egg's cleavage cell mass will form the actual embryo; the other part will elaborate the extraembryonic structures, referred to—especially in mammals—as “fetal membranes.” The set of fetal membranes comprises the yolk sac, amnion, chorion, and allantois. Fetal membranes are shed at birth by natural methods and discarded. The allantois may provide fresh approaches to old problems. Because the principal function of the allantois is to vascularize, the allantois is a very attractive organ for the study of vasculogenesis, especially as it can be isolated free of contamination from embryonic and extraembryonic tissues. © 1998 Academic Press Inc.