title: Localization of trophoblast-defined surface antigens during early mouse embryogenesis.
abstract: The binding pattern of a rabbit antiserum raised against mouse-ectoplacental-cone trophoblast on component cell populations in the pre-implantation and early post-implantation mouse embryo has been examined at the electron-microscope level using an immunoperoxidase-labelling technique. Binding was not detectable on the 1-cell stage, appeared at low levels at the 8-cell stage and was heavy on the trophectoderm and its trophoblast giant cell and extra-embryonic ectoderm descendants in the post-implantation embryo. In contrast, immunosurgically isolated 3 1/2-day inner cell masses (ICM) showed only slight labelling, whilst ICM derivatives in the 7 1/2-day embryo were unlabelled. The results indicate that the antiserum may be identifying a trophoblast-specific surface determinant(s), which appears with the differentiation of the trohectoderm and is maintained on some of the cell populations derived from this tissue at least until the early post-implantation stages.
mesh_terms: D000818:Animals; D000941:Antigens / Q000032:analysis*; D001666:Binding Sites, Antibody; D002462:Cell Membrane / Q000276:immunology; D004475:Ectoderm / Q000276:immunology; D004622:Embryo, Mammalian / Q000276:immunology; D047108:Embryonic Development; D005260:Female; D007124:Immunoenzyme Techniques; D051379:Mice; D008810:Mice, Inbred C57BL; D011247:Pregnancy; D014327:Trophoblasts / Q000276:immunology*
chemical_list: D000941:Antigens