title: Comparison of the ontogeny of specific cell surface determinants on normal and delayed implanting mouse embryos.
abstract: The ontogeny of immunospecific cell surface determinants on preimplantation mouse embryos was determined by means of an antibody-dependent complement-mediated cell lysis assay. The determinants conferring sensitivity to lysis in that assay were first observed at the late blastocyst stage on embryos recovered from normal pregnancy on day 5 or grown to an equivalent stage in vitro. Although blastocysts recovered during the dormant phase associated with delayed implantation were not lysed, those recovered following reactivation with an injection of oestrogen to the mother were sensitive. Furthermore, it was found that treating the dormant embryos with neuraminidase rendered them sensitive to lysis. These results demonstrate that the appearance of specific cell surface determinants on mouse embryos is temporally associated with the process of attachment to the uterus in both normal pregnancy and at termination of the dormant phase associated with delayed implantation. They also indicate that those determinants may be 'masked' with sialic acid during embryonic diapause. It is suggested that such cell surface determinants could be important for embryo attachment and that the mechanism responsible for their expression may explain some aspects of the synchronization between the preimplantation conceptus and its mother at the time of implantation.
authors.affiliation: Department of Cell Biology and Anatomy, Texas Tech University Health Sciences Center, Lubbock 79430.
authors.forename: R L
authors.initials: RL
authors.lastname: Klemke
authors.forename: H M
authors.initials: HM
authors.lastname: Weitlauf
mesh_terms: D000818:Animals; D000954:Antigens, Surface / Q000032:analysis*; D001755:Blastocyst / Q000187:drug effects / Q000276:immunology*; D002462:Cell Membrane / Q000276:immunology; D002478:Cells, Cultured; D003165:Complement System Proteins / Q000502:physiology; D003601:Cytotoxicity Tests, Immunologic; D010064:Embryo Implantation / Q000276:immunology*; D010065:Embryo Implantation, Delayed / Q000276:immunology*; D000939:Epitopes / Q000032:analysis*; D004958:Estradiol / Q000494:pharmacology; D005260:Female; D051379:Mice; D008815:Mice, Inbred Strains; D008858:Microscopy, Phase-Contrast; D009439:Neuraminidase / Q000494:pharmacology; D011374:Progesterone / Q000494:pharmacology
chemical_list: D000954:Antigens, Surface; D000939:Epitopes; D011374:Progesterone; D004958:Estradiol; D003165:Complement System Proteins; D009439:Neuraminidase