title: Characteristics of actin fibers and ultrastructure of the contact regions involved in the separation of blastomeres of two-cell mouse embryos, frozen-thawed without the zona pellucida.
abstract: Freezing of embryos deprived of the zona pellucida (ZP) decreases their survival rate immediately after thawing, and gives rise to the separation of their blastomeres in a high percentage of cases. We have studied the ultrastructure and the characteristics of actin fibers in the cell-to-cell contact region in mouse embryos frozen-thawed without the ZP at the two-cell stage. Our results indicate that most of the embryos that retain their blastomeres united after freezing and thawing show either the presence of a midbody, or a contact region with a close apposition of the plasma membranes but without an organized actin cortex in their contact region. Only a small percentage of embryos that retain their blastomeres united after freezing and thawing show a contact region with widely separated plasma membranes and an organized actin cytocortex.
authors.affiliation: Departament de Biologia Cellular i Fisiologia, Universitat Autònoma de Barcelona, Spain.
authors.forename: M
authors.initials: M
authors.lastname: Martí
authors.forename: M
authors.initials: M
authors.lastname: Grossmann
authors.forename: J
authors.initials: J
authors.lastname: Santaló
authors.forename: J
authors.initials: J
authors.lastname: Egozcue
authors.forename: M
authors.initials: M
authors.lastname: Ponsà
mesh_terms: D000199:Actins / Q000378:metabolism*; D000818:Animals; D001757:Blastomeres / Q000378:metabolism* / Q000648:ultrastructure*; D002448:Cell Adhesion; D002469:Cell Separation; D015925:Cryopreservation; D004622:Embryo, Mammalian / Q000166:cytology* / Q000378:metabolism*; D005260:Female; D066298:In Vitro Techniques; D008297:Male; D051379:Mice; D008854:Microscopy, Electron; D008855:Microscopy, Electron, Scanning; D008856:Microscopy, Fluorescence; D015044:Zona Pellucida / Q000648:ultrastructure
chemical_list: D000199:Actins