Xie Yan, Cheng Minghui, Lu Shan, Yuan Qilong, Yang Dongyu, Chen Ying, Pan Chen, Qiu Yurong, Xiong Bo
1Laboratory Medicine Center, Nanfang Hospital, Southern Medical University, Guangzhou, 510515 China.
2Department of Reproductive Medicine, The Second Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, 510120 China.
Cell Div. 2018 May 24;13:4. doi: 10.1186/s13008-018-0037-1. eCollection 2018.
Kinesin superfamily proteins are microtubule-based molecular motors essential for the intracellular transport of various cargos, including organelles, proteins, and RNAs. However, their exact roles during mammalian oocyte meiosis have not been fully clarified.
Herein, we investigated the critical events during porcine oocyte meiotic maturation with the treatment of Eg5-specific inhibitor monastrol. We found that Eg5 inhibition resulted in oocyte meiotic failure by displaying the poor expansion of cumulus cells and reduced rate of polar body extrusion. In the meantime, the spindle assembly and chromosome alignment were compromised, accompanied by the decreased level of acetylated α-tubulin, indicative of less stable microtubules. Impaired actin dynamics and mitochondria integrity were also observed in Eg5-inhibited oocytes. Additionally, inhibition of Eg5 caused the abnormal distribution of cortical granules and ovastacin, a cortical granule component, potentially leading to the fertilization failure.
Our findings reveal that Eg5 possesses an important function in porcine oocyte meiotic progression by regulating the organelle dynamics and arrangement.
驱动蛋白超家族蛋白是基于微管的分子马达，对于包括细胞器、蛋白质和RNA在内的各种货物的细胞内运输至关重要。然而，它们在哺乳动物卵母细胞减数分裂过程中的具体作用尚未完全阐明。
在此，我们用Eg5特异性抑制剂莫那可林处理，研究了猪卵母细胞减数分裂成熟过程中的关键事件。我们发现，Eg5抑制导致卵母细胞减数分裂失败，表现为卵丘细胞扩展不良和极体排出率降低。同时，纺锤体组装和染色体排列受到损害，伴随着乙酰化α-微管蛋白水平的降低，表明微管稳定性较差。在Eg5抑制的卵母细胞中还观察到肌动蛋白动力学和线粒体完整性受损。此外，Eg5的抑制导致皮质颗粒和皮质颗粒成分卵母细胞溶素的异常分布，可能导致受精失败。
我们的研究结果表明，Eg5通过调节细胞器的动力学和排列，在猪卵母细胞减数分裂进程中具有重要作用。
