Beta- and gamma-cytoplasmic actins are required for meiosis in mouse oocytes

Article Article scientifique Article Beta- and gamma-cytoplasmic actins are required for meiosis in mouse oocytes eng 2011 author Brockmann Céline Denise 134627 author Huarte Joachim 22247 author Dugina Vera 545863 author Challet Ludivine 583117 author Rey Emmanuelle 523328 author Conne Béatrice 117948 author Swetloff Adam 630574 author Nef Serge 0000-0001-5462-0676 29062 author Chaponnier Christine 25579 author Vassalli Jean-Dominique 21998 1025-1039 10.1095/biolreprod.111.091736 21778137 0006-3363 In mammals, female meiosis consists of two asymmetric cell divisions, which generate a large haploid oocyte and two small polar bodies. Asymmetric partitioning of the cytoplasm results from migration of the meiotic spindle toward the cortex and requires actin filaments. However, the subcellular localization and the role of the existing two cytoplasmic actin (CYA) isoforms, beta and gamma, have not been characterized. We show that beta- and gamma-CYA are differentially distributed in the maturing oocyte from late metaphase I as well as in preimplantation embryos. Gamma-CYA is preferentially enriched in oocyte cortices and is absent from all cell-cell contact areas from metaphase II until the blastocyst stage. Beta-CYA is enriched in contractile structures, at cytokinesis, at cell-cell contacts, and around the forming blastocoel. Alteration of beta- or gamma-CYA function by isoform-specific antibody microinjection suggests that gamma-CYA holds a major and specific role in the establishment and/or maintenance of asymmetry in meiosis I and in the maintenance of overall cortical integrity. In contrast, beta- and gamma-CYA, together, appear to participate in the formation and the cortical anchorage of the second meiotic spindle in waiting for fertilization. Finally, differences in gamma-CYA expression are amongst the earliest markers of cell fate determination in development. Actins/genetics/immunology/physiology Animals Antibodies/administration & dosage/immunology/pharmacology Cell Communication/physiology Cell Differentiation/physiology Cell Polarity Cells, Cultured Cytoplasm/physiology Female Meiosis/drug effects/physiology Mice Mice, Inbred Strains Mice, Transgenic Microinjections Models, Animal Oocytes/cytology/physiology Dewey 576.5 Dewey 616.07 Swiss National Science Foundation FNRS CH 135 Département de médecine génétique et développement 21D 137 Département de pathologie et immunologie 21F false 448 Mécanismes moléculaires et génétiques du développement sexuel 778 Biology of reproduction 85 5 19675b85-ecb1-485e-b05f-7fc53c6ba204 Article (Published version) Public Brockmann et al BoR 2011.pdf 1389246 application/pdf openAccess Faculté de médecine / Section de médecine fondamentale / Département de médecine génétique et développement Faculté de médecine / Section de médecine fondamentale / Département de pathologie et immunologie

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Beta- and gamma-cytoplasmic actins are required for meiosis in mouse oocytes	Biology of reproduction			2011	690	1,138

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