Control of microtubule nucleating activity in the cytoplasm of maturing mouse oocytes.
Taxol, a drug which promotes microtubule assembly, was used to assess the microtubule nucleating activity of pericentriolar material (PCM) in mouse oocytes prevented from undergoing germinal vesicle breakdown (GVBD), compared with oocytes allowed to proceed normally through GVBD and also in nucleate and anucleate oocyte fragments. Both immunofluorescence staining and ultrastructural analysis reveal that taxol induces aster formation in the cortex of oocytes undergoing GVBD, while formation of a continuous sheet of microtubule bundles parallel to the membrane is induced in metabolically GV-arrested oocytes. Since taxol also induces the formation of asters in anucleate as well as in nucleate oocyte fragments, provided they are not treated with activators of protein kinases A or C, it is concluded that microtubule nucleating activity is related to the acquisition of Maturation Promoting Factor (MPF) and does not require mixing between the nucleoplasm and cytoplasm.
Van Cauwenberge
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Laboratory of Molecular Cytology and Embryology, Faculty of Sciences, Free University of Brussels, Belgium.
Alexandre
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H
D015056:1-Methyl-3-isobutylxanthine / Q000494:pharmacology; D000470:Alkaloids / Q000494:pharmacology; D000818:Animals; D002502:Centrioles / Q000187:drug effects; D003593:Cytoplasm / Q000187:drug effects; D005260:Female; D016200:Maturation-Promoting Factor / Q000494:pharmacology; D000090204:Mesothelin; D051379:Mice; D008815:Mice, Inbred Strains; D008870:Microtubules / Q000187:drug effects*; D009865:Oocytes / Q000187:drug effects / Q000254:growth & development* / Q000648:ultrastructure; D015388:Organelles / Q000187:drug effects; D017239:Paclitaxel; D010703:Phorbol Esters / Q000494:pharmacology
D000470:Alkaloids; C000715528:Msln protein, mouse; D010703:Phorbol Esters; D016200:Maturation-Promoting Factor; D000090204:Mesothelin; D017239:Paclitaxel; D015056:1-Methyl-3-isobutylxanthine