动粒生化分子构成差异可能决定干细胞的姐妹染色单体非随机分配

Different biochemical molecular composition of kinetochores may determine non-random segregation of sister chromosomes in stem cells

根据孟德尔遗传定律,细胞有丝分裂时姐妹染色单体被随机(无选择性)分配给子代细胞。但是,近年来越来越多的实验证据表明,在组织干细胞不对称有丝分裂过程中,姐妹染色单体常常被非随机地(选择性)分配给子代细胞,目前还不清楚这种非随机分配的分子机制及其生物学意义。我们通过文献复习,提出动粒生化分子构成差异可能决定姐妹染色单体的非随机分配,而动粒生化分子构成差异可能与DNA半不连续复制引起着丝粒的表观遗传修饰不同有关。

According to Mendel＇s law of inheritance, sister chromosomes will be randomly segregated to two daughter cells during the process of mitosis. However, more and more evidences showed that non-random segregation of sister chromosomes to daughter cells were presented in the process of asymmetric mitosis of tissue stem cells. The molecular mechanism and biology significance of this non-random segregation of sister chromosomes are not clear so far. Through reviewing the literatures, we suggested that different biochemical molecular composition of kinetochores, which may be associated with the different epigenetical modification in centromere resulted from semi-discontinuocos replication of DNA, determines non-random segregation of sister chromosomes in stem cells.