Oocytes vitrification is frequently applied in assisted reproductive technologies. However, chromosomes segregation was error-prone during meiosis maturation of vitrified oocytes. The fidelity of chromosomes segregation depends on the correct kinetochore-microtubule attachments (KT-MTs). In meiosis I, the Aurora B/C would not spatially separate from the attachment sites upon bivalents stretched. Oocytes lack a mechanism for coordinating bivalent stretching and Aurora B/C inhibition in meiosis I. Thus, the KT-MTs are unstable in oocytes. In this study, we firstly found the incorrect KT-MTs were markedly increased in vitrified oocytes. The Aurora B/C activity in vitrified oocytes was significantly increased when the bivalents were stretched. This Aurora B/C activity could not induce a SAC response, as the SAC protein Mad2 was significantly decreased during MI stage in vitrified oocytes. Thus, the KT-MTs in vitrified oocytes were error-prone. This study, for the first time, revealed the mechanism of the incorrect KT-MTs occurred in vitrified oocytes and provided a theoretical basis for further improvement of oocytes vitrification.

卵母细胞玻璃化常用于辅助生殖技术。但是，在玻璃化卵母细胞的减数分裂成熟过程中，染色体分离容易出错。染色体分离的保真度取决于正确的动粒-微管附件（KT-MT）。在减数分裂I中，Aurora B / C在二价键拉伸后不会在空间上与附着位点分离。卵母细胞缺乏协调减数分裂I中二价拉伸和Aurora B / C抑制的机制。因此，KT-MT在卵母细胞中不稳定。在这项研究中，我们首先发现玻璃化卵母细胞中不正确的KT-MTs明显增加。当二价被拉伸时，玻璃化卵母细胞中的Aurora B / C活性显着增加。这种Aurora B / C活动无法诱导SAC响应，因为在玻璃化卵母细胞的MI期，SAC蛋白Mad2明显降低。因此，玻璃化卵母细胞中的KT-MT容易出错。这项研究首次揭示了玻璃化卵母细胞中不正确的KT-MT发生的机制，并为进一步改善卵母细胞玻璃化提供了理论依据。