In female meiosis, oocyte meiotic maturation is a form of asymmetric cell division, producing the first polar body and a large oocyte, in which the asymmetry of oocyte meiotic division depends on spindle migration and positioning, and cortical polarization. In this study, we conclude that WDR62 (WD40-repeat protein 62) plays an important role in asymmetric meiotic division during mouse oocyte maturation. Our initial study demonstrated that WDR62 mainly co-localized with chromosomes during mouse oocyte meiotic maturation. Interference of Wdr62 by siRNA microinjection did not affect germinal vesicle breakdown (GVBD) but compromised the first polar body extrusion (PBE) with the large polar bodies generated, which is coupled with a higher incidence of spindle abnormality and chromosome misalignment. Further analysis concluded that loss of WDR62 blocked asymmetric spindle positioning and actin cap formation, which should be responsible for large polar body extrusion. Moreover, WDR62 decline intervened with the Arp2/3 complex, an upstream regulator for the cortical actin. Besides for p-MAPK, a critical regulator for the asymmetric division of oocyte, WDR62-depleted oocytes showed perturbation only in localization pattern but not expression level. In summary, our study defines WDR62 as an essential cytoskeletal regulator of spindle migration and asymmetric division during mouse oocyte meiotic maturation.

中文翻译：

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WDR62是小鼠卵母细胞减数分裂成熟过程中纺锤体迁移和不对称胞质分裂的新型参与者。

在女性减数分裂中，卵母细胞减数分裂成熟是不对称细胞分裂的一种形式，产生第一个极体和一个大卵母细胞，其中卵母细胞减数分裂的不对称性取决于纺锤体的迁移和定位以及皮层极化。在这项研究中，我们得出的结论是WDR62（WD40重复蛋白62）在小鼠卵母细胞成熟过程中的不对称减数分裂中起着重要作用。我们的初步研究表明，WDR62在小鼠卵母细胞减数分裂成熟过程中主要与染色体共定位。siRNA显微注射对Wdr62的干扰不会影响生小泡的破裂（GVBD），但会损害首次极性体挤出（PBE）并产生较大的极性体，并伴有更高的纺锤体异常和染色体错位发生率。进一步的分析得出结论，WDR62的丢失会阻止不对称的纺锤体定位和肌动蛋白帽的形成，这应负责大极性体的挤出。此外，WDR62的下降与Arp2 / 3复合物（一种皮质肌动蛋白的上游调节剂）介入。除了p-MAPK（卵母细胞不对称分裂的关键调节剂）外，消耗WDR62的卵母细胞仅在定位模式上表现出扰动，而在表达水平上却没有表现出扰动。总而言之，我们的研究将WDR62定义为小鼠卵母细胞减数分裂成熟过程中纺锤体迁移和不对称分裂的重要细胞骨架调节剂。WDR62耗尽的卵母细胞是卵母细胞不对称分裂的关键调节剂，仅在定位模式中表现出扰动，而在表达水平上却没有表现出扰动。总而言之，我们的研究将WDR62定义为小鼠卵母细胞减数分裂成熟过程中纺锤体迁移和不对称分裂的重要细胞骨架调节剂。WDR62耗尽的卵母细胞是卵母细胞不对称分裂的关键调节剂，仅在定位模式中表现出扰动，而在表达水平上却没有表现出扰动。总而言之，我们的研究将WDR62定义为小鼠卵母细胞减数分裂成熟过程中纺锤体迁移和不对称分裂的重要细胞骨架调节剂。