title: True Nondisjunction of Whole Bivalents in Oocytes with Attachment and Congression Defects.
abstract: Chromosome segregation in mammalian oocytes is prone to errors causing aneuploidy with consequences such as precocious termination of development or severe developmental disorders. Aneuploidy also represents a serious problem in procedures utilizing mammalian gametes and early embryos in vitro. In our study, we focused on congression defects during meiosis I and observed whole nondisjoined bivalents in meiosis II as a direct consequence, together with a substantially delayed first polar body extrusion. We also show that the congression defects are accompanied by less stable attachments of the kinetochores. Our results describe a process by which congression defects directly contribute to aneuploidy.
authors.affiliation: Veterinary Research Institute, Brno, Czech Republic.
authors.forename: Martin
authors.initials: M
authors.lastname: Sodek
authors.forename: Kristina
authors.initials: K
authors.lastname: Kovacovicova
authors.forename: Martin
authors.initials: M
authors.lastname: Anger
mesh_terms: D000782:Aneuploidy; D000818:Animals; D020090:Chromosome Segregation / Q000235:genetics*; D005260:Female; D018386:Kinetochores / Q000378:metabolism; D008297:Male; D008540:Meiosis / Q000235:genetics*; D051379:Mice; D008810:Mice, Inbred C57BL; D018613:Microscopy, Confocal; D008870:Microtubules / Q000378:metabolism; D009630:Nondisjunction, Genetic; D009865:Oocytes / Q000378:metabolism*; D059008:Time-Lapse Imaging / Q000379:methods