State Key Laboratory of Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China.
Cell Cycle. 2012 Mar 1;11(5):909-16. doi: 10.4161/cc.11.5.19384.
The Ska (spindle and kinetochore-associated) complex is composed of three proteins: Ska1, Ska2 and Ska3. It is required for stabilizing kinetochore-microtubule (KT-MT) interactions and silencing spindle checkpoint during mitosis. However, its roles in meiosis remain unclear. The present study was designed to investigate the localization and function of the Ska complex during mouse oocyte meiotic maturation. Our results showed that the localization and function of Ska complex in mouse oocyte meiosis differ in part from those in mitosis. Injection of low dose exogenous Myc-Ska mRNA showed that, instead of localizing to the kinetochores (KTs) and mediating KT-MT interactions from pro-metaphase to mid-anaphase stages as in mitosis, the members of the Ska complex were only localized on spindle microtubules from the Pro-MI to MII stages in mouse oocyte meiosis. Time-lapse live imaging analysis showed that knockdown of any member of the Ska complex by Morpholino injection into mouse oocytes resulted in spindle movement defects and enlarged polar bodies. Depletion of the whole Ska complex disrupted the stability of the anaphase spindle and influenced the extrusion of the first polar body. Taken together, these results show that the Ska complex plays an important role in meiotic spindle migration and anaphase spindle stability during mouse oocyte maturation.
Ska（纺锤体和着丝粒相关）复合物由三种蛋白质组成：Ska1、Ska2 和 Ska3。它对于稳定着丝粒微管（KT-MT）相互作用和沉默有丝分裂期间的纺锤体检查点是必需的。然而，其在减数分裂中的作用尚不清楚。本研究旨在研究 Ska 复合物在小鼠卵母细胞减数分裂成熟过程中的定位和功能。我们的结果表明，Ska 复合物在小鼠卵母细胞减数分裂中的定位和功能部分不同于有丝分裂。注射低剂量外源性 Myc-Ska mRNA 表明，Ska 复合物的成员并未像有丝分裂那样从前期到中期定位在动粒（KTs）并介导 KT-MT 相互作用，而是仅从 Pro-MI 到 MII 阶段定位在纺锤体微管上在小鼠卵母细胞减数分裂中。延时活细胞成像分析表明，通过向小鼠卵母细胞中注射 Morpholino 敲低 Ska 复合物的任何成员都会导致纺锤体运动缺陷和扩大极体。整个 Ska 复合物的耗竭破坏了后期纺锤体的稳定性，并影响了第一极体的挤出。总之，这些结果表明 Ska 复合物在小鼠卵母细胞成熟过程中的减数分裂纺锤体迁移和后期纺锤体稳定性中发挥重要作用。
