title: Non-invasive method to assess genotoxicity of nocodazole interfering with spindle formation in mammalian oocytes.
abstract: Trisomies due to nondisjunction in oogenesis are still a major cause of genetic diseases in humans. In this study, we analysed spindle morphology of in vitro matured nocodazole-exposed mouse oocytes by novel non-invasive Polscope-microscopy, and compared images to those obtained by anti-tubulin immunofluorescence of fixed oocytes. Polscope revealed a reduction in the numbers of oocytes expressing a birefringent spindle, and alterations in spindle morphology at concentrations of nocodazole below those inducing detectable aberrations in immunofluorescence. Hyperploidy increased significantly at a concentration of 40 nM nocodazole in mouse metaphase II oocytes, similar to thresholds inducing nondisjunction in cultured human lymphocytes. In conclusion, Polscope represents a novel highly sensitive, non-invasive method to identify chemicals inducing severe spindle aberrations that predispose mammalian oocytes to nondisjunction. Polscope may provide information on the functionality of the spindle in experimental studies but is also compatible with clinical trials in human assisted reproduction due to its non-invasive nature.
authors.affiliation: Faculty of Biology, Institute of Gene Technology/Microbiology, University of Bielefeld, D-33501 Bielefeld, Germany.
authors.forename: Ying
authors.initials: Y
authors.lastname: Shen
authors.forename: Ilse
authors.initials: I
authors.lastname: Betzendahl
authors.forename: Fengyun
authors.initials: F
authors.lastname: Sun
authors.forename: Hans-Rudolf
authors.initials: HR
authors.lastname: Tinneberg
authors.forename: Ursula
authors.initials: U
authors.lastname: Eichenlaub-Ritter
mesh_terms: D000782:Aneuploidy; D000818:Animals; D001718:Birefringence; D020090:Chromosome Segregation / Q000187:drug effects; D033481:Chromosomes, Mammalian / Q000187:drug effects / Q000648:ultrastructure; D005260:Female; D066298:In Vitro Techniques; D008540:Meiosis / Q000187:drug effects; D008677:Metaphase / Q000187:drug effects; D051379:Mice; D008815:Mice, Inbred Strains; D008856:Microscopy, Fluorescence; D008859:Microscopy, Polarization; D008870:Microtubules / Q000187:drug effects / Q000648:ultrastructure; D009153:Mutagens / Q000633:toxicity*; D015739:Nocodazole / Q000633:toxicity*; D009865:Oocytes / Q000187:drug effects* / Q000648:ultrastructure; D008941:Spindle Apparatus / Q000187:drug effects* / Q000648:ultrastructure
chemical_list: D009153:Mutagens; D015739:Nocodazole