OLA1 is responsible for normal spindle assembly and SAC activation in mouse oocytes
OLA1 is responsible for normal spindle assembly and SAC activation in mouse oocytes
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OLA1 负责小鼠卵母细胞中正常纺锤体组装和 SAC 激活
作者：
Xie Di;Zhang Juan;Ding JinLi;Yang Jing;Zhang Yan
OLA1是GTPase蛋白家族的成员；与其他成员不同的是，它同时具有GTPase和ATP酶活性，并且比GTP更有效地结合和水解ATP。OLA1参与细胞增殖、氧化反应、蛋白质合成和肿瘤发生。然而，对于卵母细胞减数分裂是否也需要OLA1仍是未知的。方法研究OLA1在小鼠卵母细胞减数分裂中的定位、表达和功能。利用免疫荧光和共聚焦显微镜研究了OLA1在小鼠卵母细胞中的定位模式。此外，在小鼠减数分裂过程中，使用诺可唑治疗来确定OLA1的纺锤状位置。Western blot检测OLA1在小鼠卵母细胞中的表达规律。采用siRNA微注射的方法探讨OLA1在小鼠卵母细胞减数分裂中的作用。此外，利用染色体扩展法研究纺锤体组装检查点（SAC）的活性。结果免疫荧光染色显示，OLA1在生发小泡期细胞质中分布均匀。减数分裂恢复（GVBD）后，OLA1与纺锤体共定位，通过诺可达唑处理实验进一步鉴定。OLA1基因的表达降低了生发小泡的破坏进程，最终导致极体挤压率降低。免疫荧光分析表明，OLA1基因的敲低导致纺锤体组装异常，OLA1- rnai -卵母细胞中的多极纺锤体证明了这一点。在gvbd培养6小时后，在OLA1敲低的卵母细胞中，观察到卵母细胞过早进入后期/端粒期I （A/TI）的比例增加，这表明OLA1的缺失导致同源染色体过早分离。此外，染色体扩散分析表明，OLA1敲低导致的早期晚期发作是由于SAC的过早失活。综上所述，我们认为OLA1在卵母细胞减数分裂的GVBD、纺锤体组装和SAC激活维持中起重要作用。
Background OLA1 is a member of the GTPase protein family; unlike other members, it possess both GTPase and ATPase activities, and can bind and hydrolyze ATP more efficiently than GTP. OLA1 participates in cell proliferation, oxidative response, protein synthesis and tumorigenesis. However, whether OLA1 is also required for oocyte meiosis is still unknown. Methods In this study, the localization, expression, and functions of OLA1 in the mouse oocyte meiosis were examined. Immunofluorescent and confocal microscopy were used to explore the location pattern of OLA1 in the mouse oocyte. Moreover, nocodazole treatment was used to confirm the spindle-like location of OLA1 during mouse meiosis. Western blot was used to explore the expression pattern of OLA1 in the mouse oocyte. Microinjection of siRNA was used to explore the OLA1 functions in the mouse oocyte meiosis. In addition, chromosome spreading was used to investigate the spindle assembly checkpoint (SAC) activity. Results Immunofluorescent staining showed that OLA1 evenly distributed in the cytoplasm at germinal vesicle (GV) stage. After meiosis resumption (GVBD), OLA1 co-localized with spindles, which was further identified by nocodazole treatment experiments. Knockdown of OLA1 impaired the germinal vesicle breakdown progression and finally resulted in a lower polar body extrusion rate. Immunofluorescence analysis indicated that knockdown of OLA1 led to abnormal spindle assembly, which was evidenced by multipolar spindles in OLA1-RNAi-oocytes. After 6 h post-GVBD in culture, an increased proportion of oocyte which has precociously entered into anaphase/telephase I (A/TI) was observed in OLA1-knockdown oocytes, suggesting that loss of OLA1 resulted in the premature segregation of homologous chromosomes. In addition, the chromosome spread analysis suggested that OLA1 knockdown induced premature anaphase onset was due to the precocious inactivation of SAC. Taken together, we concluded that OLA1 plays important role in GVBD, spindle assembly and SAC activation maintenance in oocyte meiosis.
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影响因子：
3.9
作者：
Sanders JR;Jones KT
通讯作者：
Jones KT
DOI：
10.1002/9780470687970.ch10
发表时间：
2010-04
期刊：
--
影响因子：
--
作者：
J. Dumont;S. Brunet
通讯作者：
J. Dumont;S. Brunet
BRCA1 是小鼠卵母细胞减数分裂纺锤体组装和纺锤体组装检查点激活所必需的。
影响因子：
3.6
作者：
Xiong, Bo;Li, Sen;Sun, Qing-Yuan
通讯作者：
Sun, Qing-Yuan
影响因子：
4.8
作者：
Ma, Rujun;Hou, Xiaojing;Wang, Qiang
通讯作者：
Wang, Qiang
影响因子：
3.7
作者：
Li M;Li S;Yuan J;Wang ZB;Sun SC;Schatten H;Sun QY
通讯作者：
Sun QY