Repression of harmful meiotic recombination in centromeric regions.
Repression of harmful meiotic recombination in centromeric regions.
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DOI：
10.1016/j.semcdb.2016.01.042
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发表时间：
2016-06
影响因子：
7.3
通讯作者：
Smith GR
中科院分区：
文献类型：
--
作者：
Nambiar M;Smith GR
在减数分裂的第一次分裂中，同源染色体的分离使染色体数量减少了一半。在大多数物种中，姐妹染色单体的凝聚力和同源染色体之间的相互重组(交换)对于在第一次减数分裂过程中提供适当的染色体分离信号是必不可少的。交叉并不均匀地分布在整个基因组中，而是在着丝粒和着丝粒附近受到抑制。发生在着丝粒附近或在着丝粒上的罕见杂交干扰了适当的分离，并可能产生非整倍体后代，这可能是严重缺陷或无法存活的。我们在这里回顾了着丝粒内和着丝粒周围如何发生交叉以及如何防止这种现象。着丝粒抑制的分子机制直到现在才被阐明。然而，在理解互换、染色体结构和着丝粒功能方面的快速进展有望解释如何在某些染色体区域避免潜在有害的互换，而在其他染色体区域允许有益的互换。
During the first division of meiosis, segregation of homologous chromosomes reduces the chromosome number by half. In most species, sister chromatid cohesion and reciprocal recombination (crossing-over) between homologous chromosomes are essential to provide tension to signal proper chromosome segregation during the first meiotic division. Crossovers are not distributed uniformly throughout the genome and are repressed at and near the centromeres. Rare crossovers that occur too near or in the centromere interfere with proper segregation and can give rise to aneuploid progeny, which can be severely defective or inviable. We review here how crossing-over occurs and how it is prevented in and around the centromeres. Molecular mechanisms of centromeric repression are only now being elucidated. However, rapid advances in understanding crossing-over, chromosome structure, and centromere functions promise to explain how potentially deleterious crossovers are avoided in certain chromosomal regions while allowing beneficial crossovers in others.