未成熟卵母细胞（卵泡核期，GV）的冷冻保存可以避免卵巢刺激周期，对患有激素敏感肿瘤的患者更为友好。然而，冷冻保存后的GV卵母细胞在体外成熟往往导致非整倍体，其潜在机制尚不清楚。稳定的纺锤极对于准确的染色体分离至关重要。无中心微管有机化中心（aMTOCs）会发生断裂和再聚集以形成纺锤极。GVBD之后，通过分子交换因子Ran，促进微管核化和aMTOCs的断裂，该过程对于aMTOCs的断裂起到重要作用。本研究发现，冷冻保存可能通过降低周围染色质中Ran的水平，减少了微管密度，降低了pKIF11的定位，从而减少了aMTOCs的断裂并形成更为集中的纺锤极，最终导致非整倍体。本研究揭示了冷冻保存卵母细胞异常纺锤极形成的机制，并为进一步提高冷冻保存卵母细胞质量提供了理论支持。版权所有 © 2023 Elsevier Inc. 保留所有权利。

Immature oocyte (germinal vesicle stage, GV) vitrification can avoid a cycle of ovarian stimulation, which is friendly to patients with hormone-sensitive tumors. However, the in vitro maturation of vitrification-thawed GV oocyte usually results in aneuploidy, and the underlying mechanism remains unclear. Stable spindle poles are important for accurate chromosome segregation. Acentriolar microtubule-organizing centers (aMTOCs) undergo fragmentation and reaggregation to form spindle poles. Microtubule nucleation is facilitated via the perichromosome Ran after GVBD, which plays an important role in aMTOCs fragmentation. This study showed that vitrification may reduce microtubule density by decreasing perichromosomal Ran levels, which reduced the localization of pKIF11, thereby decreased the fragmentation of aMTOCs and formed a more focused spindle pole, ultimately resulted in aneuploidy. This study revealed the mechanism of abnormal spindle pole formation in vitrified oocytes and offered a theoretical support to further improve the quality of vitrified oocytes.Copyright © 2023 Elsevier Inc. All rights reserved.