Dynamics of uterine glycoconjugate expression and function

Embryo attachment to the apical surface of the uterine epithelium is an eve nt found in all mammalian species. Consequently, aspects of this process ma y be shared and considered as general principles in implantation strategies across species. This review focuses on studies implicating mucin glycoprot eins disposed at the apical surface of uterine epithelia as antiadhesive mo lecules that block embryo attachment. As such, mucins must be removed, at l east locally, to permit intimate contact between trophectoderm and uterine epithelia. Subsequently, we consider the role that heparan sulfate proteogl ycans (HSPGs) and HSPG-binding proteins play in tethering embryos to the ap ical surface of uterine epithelia during the attachment process.