title: Arp2/3 complex regulates asymmetric division and cytokinesis in mouse oocytes.
abstract: Mammalian oocyte meiotic maturation involves oocyte polarization and a unique asymmetric division, but until now, the underlying mechanisms have been poorly understood. Arp2/3 complex has been shown to regulate actin nucleation and is widely involved in a diverse range of processes such as cell locomotion, phagocytosis and the establishment of cell polarity. Whether Arp2/3 complex participates in oocyte polarization and asymmetric division is unknown. The present study investigated the expression and functions of Arp2/3 complex during mouse oocyte meiotic maturation. Immunofluorescent staining showed that the Arp2/3 complex was restricted to the cortex, with a thickened cap above the meiotic apparatus, and that this localization pattern was depended on actin. Disruption of Arp2/3 complex by a newly-found specific inhibitor CK666, as well as by Arpc2 and Arpc3 RNAi, resulted in a range of effects. These included the failure of asymmetric division, spindle migration, and the formation and completion of oocyte cytokinesis. The formation of the actin cap and cortical granule-free domain (CGFD) was also disrupted, which further confirmed the disruption of spindle migration. Our data suggest that the Arp2/3 complex probably regulates oocyte polarization through its effect on spindle migration, asymmetric division and cytokinesis during mouse oocyte meiotic maturation.
authors.affiliation: Department of Animal Sciences, Chungbuk National University, Cheongju, Republic of Korea.
authors.forename: Shao-Chen
authors.initials: SC
authors.lastname: Sun
authors.forename: Zhen-Bo
authors.initials: ZB
authors.lastname: Wang
authors.forename: Yong-Nan
authors.initials: YN
authors.lastname: Xu
authors.forename: Seung-Eun
authors.initials: SE
authors.lastname: Lee
authors.forename: Xiang-Shun
authors.initials: XS
authors.lastname: Cui
authors.forename: Nam-Hyung
authors.initials: NH
authors.lastname: Kim
mesh_terms: D051376:Actin-Related Protein 2-3 Complex / Q000378:metabolism*; D000199:Actins / Q000378:metabolism; D000818:Animals; D002454:Cell Differentiation / Q000187:drug effects; D016764:Cell Polarity / Q000187:drug effects; D003571:Cytochalasin B / Q000494:pharmacology; D048749:Cytokinesis / Q000187:drug effects; D003594:Cytoplasmic Granules / Q000187:drug effects / Q000378:metabolism; D007211:Indoles / Q000494:pharmacology; D008540:Meiosis / Q000187:drug effects; D051379:Mice; D008954:Models, Biological; D009865:Oocytes / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism*; D021381:Protein Transport / Q000187:drug effects; D034622:RNA Interference / Q000187:drug effects; D008941:Spindle Apparatus / Q000187:drug effects / Q000378:metabolism
chemical_list: D051376:Actin-Related Protein 2-3 Complex; D000199:Actins; C543733:CK-0944666; D007211:Indoles; D003571:Cytochalasin B