CENP-A Regulates Chromosome Segregation during the First Meiosis of Mouse Oocytes

Proper chromosome separation in both mitosis and meiosis depends on the correct connection between kinetochores of chromosomes and spindle microtubules. Kinetochore dysfunction can lead to unequal distribution of chromosomes during cell division and result in aneuploidy, thus kinetochores are critical for faithful segregation of chromosomes. Centromere protein A(CENP-A) is an important component of the inner kinetochore plate. Multiple studies in mitosis have found that deficiencies in CENP-A could result in structural and functional changes of kinetochores, leading to abnormal chromosome segregation, aneuploidy and apoptosis in cells. Here we report the expression and function of CENP-A during mouse oocyte meiosis. Our study found that microinjection of CENP-A blocking antibody resulted in errors of homologous chromosome segregation and caused aneuploidy in eggs. Thus, our findings provide evidence that CENP-A is critical for the faithful chromosome segregation during mammalian oocyte meiosis.

抗氧化剂对小鼠卵母细胞老化延缓作用的研究

目的:探讨重金属耦合剂(乙二胺四乙酸和柠檬酸钠)与抗氧化剂(硫辛酸和乙酰肉碱)对小鼠卵子数目、线粒体和纺锤体老化的影响。方法:随机将C57BL/6雌性小鼠分为4组,重金属耦合剂组(A组)、抗氧化剂组(B组)、混合组(C组)和正常空白对照组(D组),每组48只。分别在饮用水中添加重金属耦合剂和/或抗氧化剂,并于饲养3个月、6个月、9个月和12个月后测定卵子数目、线粒体膜电位和纺锤体结构等指标。结果:小鼠卵子数和线粒体活性均随年龄增长而下降和减弱,纺锤体异常率随时间的延长而升高;在同一年龄阶段中,与A组和D组相比,B组和C组的卵子数目较多,长时间作用后,线粒体活性偏高,而纺锤体异常率偏低。结论:饮用水中添加抗氧化剂硫辛酸和乙酰肉碱可有延迟卵母细胞老化的作用。