title: Cep55 regulates spindle organization and cell cycle progression in meiotic oocyte.
abstract: Cep55 is a relatively novel member of the centrosomal protein family. Here, we show that Cep55 is expressed in mouse oocytes from the germinal vesicle (GV) to metaphase II (MII) stages. Immuostaining and confocal microscopy as well as time lapse live imaging after injection of mRNA encoding fusion protein of Cep55 and GFP identified that Cep55 was localized to the meiotic spindle, especially to the spindle poles at metaphase, while it was concentrated at the midbody in telophase in meiotic oocytes. Knockdown of Cep55 by specific siRNA injection caused the dissociation of γ-tubulin from the spindle poles, resulting in severely defective spindles and misaligned chromosomes, leading to metaphase I arrest and failure of first polar body (PB1) extrusion. Correspondingly, cyclin B accumulation and spindle assembly checkpoint (SAC) activation were observed in Cep55 knockdown oocytes. Our results suggest that Cep55 may act as an MTOC-associated protein regulating spindle organization, and thus cell cycle progression during mouse oocyte meiotic maturation.
authors.affiliation: The Reproductive Medical Center, the First Affiliated Hospital, Zhengzhou University, Zhengzhou, 450052 China.
authors.forename: Zhao-Yang
authors.initials: ZY
authors.lastname: Xu
authors.affiliation: State Key Laboratory of Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100020 China.
authors.forename: Xue-Shan
authors.initials: XS
authors.lastname: Ma
authors.affiliation: State Key Laboratory of Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100020 China.
authors.forename: Shu-Tao
authors.initials: ST
authors.lastname: Qi
authors.affiliation: State Key Laboratory of Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100020 China.
authors.forename: Zhen-Bo
authors.initials: ZB
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100020 China.
authors.forename: Lei
authors.initials: L
authors.lastname: Guo
authors.affiliation: Department of Veterinary Pathobiology, University of Missouri-Columbia, MO 65211, USA.
authors.forename: Heide
authors.initials: H
authors.lastname: Schatten
authors.affiliation: State Key Laboratory of Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100020 China.
authors.forename: Qing-Yuan
authors.initials: QY
authors.lastname: Sun
authors.affiliation: The Reproductive Medical Center, the First Affiliated Hospital, Zhengzhou University, Zhengzhou, 450052 China.
authors.forename: Ying-Pu
authors.initials: YP
authors.lastname: Sun
mesh_terms: D000705:Anaphase; D000818:Animals; D002453:Cell Cycle; D018797:Cell Cycle Proteins / Q000378:metabolism*; D033481:Chromosomes, Mammalian / Q000378:metabolism; D056744:Cyclin B1 / Q000378:metabolism; D005260:Female; D055785:Gene Knockdown Techniques; D059566:M Phase Cell Cycle Checkpoints; D051379:Mice; D009865:Oocytes / Q000166:cytology* / Q000378:metabolism*; D059705:Polar Bodies / Q000378:metabolism; D021381:Protein Transport; D008941:Spindle Apparatus / Q000378:metabolism*; D013347:Subcellular Fractions / Q000378:metabolism; D014404:Tubulin / Q000378:metabolism
chemical_list: D018797:Cell Cycle Proteins; C000610639:Cep55 protein, mouse; D056744:Cyclin B1; D014404:Tubulin