Developmentally regulated expression of cell surface carbohydrates during mouse embryogenesis

AbstractCell surface carbohydrates undergo marked alterations during mouse embryogenesis. In preimplantation embryos, many carbohydrate markers show stage‐specific expression in diverse ways. In early postimplantation embryos, certain carbohydrate markers are localized in defined regions in the embryo. Important carriers of stage‐specific carbohydrates are the lactoseries structure (Galβ1→4GlcNAc) and the globoseries structure (Galα1→4Gal). Notably, the glycoprotein‐bound large carbohydrate of poly‐N‐acetyllactosamine‐type ([Galβ1→4GlcNAcβ1 → 3]n) carries a number of markers preferentially expressed in early embryonic cells. These markers are of practical value in analyzing embryogenesis and cell differentiation. For example, in order to monitor in vitro differentiation of multipotential embryonal carcinoma cells, stage‐specific embryonic antigen‐1 (SSEA‐1) and the Lotus agglutinin receptor have been used as markers of the undifferentiated cells, and the Dolichos agglutinin receptor has been used as a marker of extraembryonic endoderm cells. Developmental control of cell surface carbohydrates is attained by controlled expression of activities of key glycosyltransferases; for exampl