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SUMO‐1 plays crucial roles for spindle organization, chromosome congression, and chromosome segregation during mouse oocyte meiotic maturation
Author(s) -
Yuan YiFeng,
Zhai Rui,
Liu XiaoMing,
Khan Hamid Ali,
Zhen YanHong,
Huo LiJun
Publication year - 2014
Publication title -
molecular reproduction and development
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.745
H-Index - 105
eISSN - 1098-2795
pISSN - 1040-452X
DOI - 10.1002/mrd.22339
Subject(s) - biology , oocyte , meiosis , chromosome segregation , microbiology and biotechnology , chromosome , genetics , gene , embryo
Summary S mall u biquitin‐related mo difier‐1 (SUMO‐1)‐dependent modifications of many target proteins are involved in a range of intracellular processes. Previous studies reported the localization of SUMO‐1 during oocyte meiosis, and that overexpression of Sen trin/SUMO‐specific p rotease 2 (SENP2), a de‐SUMOylation protease, altered SUMO‐modified proteins, and caused defects in metaphase‐II spindle organization. In this study, we detailed the consequences of SUMO‐1‐mediated SUMOylation by either inhibition of SUMO‐1 or UBC9 with a specific antibody or their depletion by specific siRNA microinjection. Inhibition or depletion of SUMO‐1 or UBC9 in germinal vesicle (GV)‐stage oocytes decreased the rates of germinal vesicle breakdown and first polar body (PB1) extrusion; caused defective spindle organization and misaligned chromosomes; and led to aneuploidy in matured oocytes. Stage‐specific antibody injections suggested that SUMO‐1 functions before anaphase I during PB1 extrusion. Further experiments indicated that the localization of γ‐tubulin was disordered after SUMO‐1 inhibition, and that SUMO‐1 depletion disrupted kinetochore‐microtubule attachment at metaphase I. Moreover, SUMO‐1 inhibition resulted in less‐condensed chromosomes, altered localization of REC8 and securin, and reduced BUBR1 accumulation at the centromere. On the other hand, overexpression of SUMO‐1 in GV‐stage oocytes had no significant effect on oocyte maturation. In conclusion, our results implied that SUMO‐1 plays crucial roles during oocyte meiotic maturation, specifically involving spindle assembly and chromosome behavior, by regulating kinetochore‐microtubule attachment and the localization of γ‐tubulin, BUBR1, REC8, and securin. Mol. Reprod. Dev . 81: 712–724, 2014. © 2014 Wiley Periodicals, Inc.