Septin 7 is required for orderly meiosis in mouse oocytes.
Septin 7 is a conserved GTP-binding protein. In this study, we examined the localization and functions of Septin 7 during mouse oocyte meiotic maturation. Immunofluorescent analysis showed that intrinsic Septin 7 localized to the spindles from the pro-MI stage to the MII stage. Knockdown of Septin 7 by siRNA microinjection caused abnormal spindles and affected extrusion of the first polar body. Septin 7 mRNA tagged with myc was injected into GV stage oocytes to overexpress Septin 7. Overexpressed Myc-Septin 7 localized to the spindle and beneath the plasma membrane displaying long filaments. Fluorescence intensity of spindle α-tubulin in myc-Septin 7-injected oocytes was weaker than that of the control group, demonstrating that Septin 7 may influence recruitment of α-tubulin to spindles. MII oocytes injected with myc-Septin 7 exhibited abnormal chromosome alignment, and parthenogenetic activation failed to allow extrusion of the second polar body, suggesting that overexpression of Septin 7 may affect extrusion of the polar body by disturbing the alignment of chromosomes and regulating α-tubulin recruitment to spindles. In summary, Septin 7 may regulate meiotic cell cycle progression by affecting microtubule cytoskeletal dynamics in mouse oocytes.
State Key Laboratory of Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Reproductive Medicine Center, Peking University People's Hospital, Beijing, China.
Sen
S
Li
Xiang-Hong
XH
Ou
Liang
L
Wei
Zhen-Bo
ZB
Wang
Qing-Hua
QH
Zhang
Ying-Chun
YC
Ouyang
Yi
Y
Hou
Heide
H
Schatten
Qing-Yuan
QY
Sun
D000704:Analysis of Variance; D000818:Animals; D020090:Chromosome Segregation / Q000235:genetics / Q000502:physiology*; D003599:Cytoskeleton / Q000502:physiology*; D017931:DNA Primers / Q000235:genetics; D055785:Gene Knockdown Techniques; D015151:Immunoblotting; D008540:Meiosis / Q000502:physiology*; D051379:Mice; D008856:Microscopy, Fluorescence; D008870:Microtubules / Q000378:metabolism* / Q000502:physiology; D009865:Oocytes / Q000166:cytology* / Q000378:metabolism / Q000502:physiology; D034741:RNA, Small Interfering / Q000235:genetics; D058112:Septins / Q000235:genetics / Q000378:metabolism* / Q000502:physiology; D014404:Tubulin / Q000378:metabolism
D017931:DNA Primers; D034741:RNA, Small Interfering; D014404:Tubulin; C512895:Sept7 protein, mouse; D058112:Septins