Cheng Jin-Mei, Liu Yi-Xun
State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China.
Institute of Reproductive Medicine, School of Medicine, Nantong University, Nantong 226001, China.
Int J Mol Sci. 2017 Jul 22;18(7):1578. doi: 10.3390/ijms18071578.
Aneuploidy is a leading genetic cause of birth defects and lower implantation rates in humans. Most errors in chromosome number originate from oocytes. Aneuploidy in oocytes increases with advanced maternal age. Recent studies support the hypothesis that cohesion deterioration with advanced maternal age represents a leading cause of age-related aneuploidy. Cohesin generates cohesion, and is established only during the premeiotic S phase of fetal development without any replenishment throughout a female's period of fertility. Cohesion holds sister chromatids together until meiosis resumes at puberty, and then chromosome segregation requires the release of sister chromatid cohesion from chromosome arms and centromeres at anaphase I and anaphase II, respectively. The time of cohesion cleavage plays an important role in correct chromosome segregation. This review focuses specifically on the causes and effects of age-related cohesion deterioration in female meiosis.
非整倍体是人类出生缺陷和着床率降低的主要遗传原因。大多数染色体数目错误源于卵母细胞。卵母细胞中的非整倍体随着母亲年龄的增长而增加。最近的研究支持这样一种假说，即随着母亲年龄的增长，黏连蛋白的退化是与年龄相关的非整倍体的主要原因。黏连蛋白产生黏连，并且仅在胎儿发育的减数分裂前S期建立，在女性的生育期内没有任何补充。黏连将姐妹染色单体连接在一起，直到青春期减数分裂恢复，然后染色体分离分别需要在减数第一次分裂后期和减数第二次分裂后期从染色体臂和着丝粒释放姐妹染色单体黏连。黏连蛋白裂解的时间在正确的染色体分离中起重要作用。本综述特别关注女性减数分裂中与年龄相关的黏连蛋白退化的原因和影响。
