Department of Biological Sciences, Seoul National University, Gwanak-ro 1, Gwanak-gu, Seoul, 08827, Korea.
Aging Research Institute, Korea Research Institute of Bioscience and Biotechnology, Gwahak-ro 125, Daejeon, 34141, Korea.
Bioessays. 2020 Jun;42(6):e1900177. doi: 10.1002/bies.201900177. Epub 2020 Apr 1.
DNA damage repair within telomeres are suppressed to maintain the integrity of linear chromosomes, but the accidental activation of repairs can lead to genome instability. This review develops the concept that mechanisms to repair DNA damage in telomeres contribute to genetic variability and karyotype evolution, rather than catastrophe. Spontaneous breaks in telomeres can be repaired by telomerase, but in some cases DNA repair pathways are activated, and can cause chromosomal rearrangements or fusions. The resultant changes can also affect subtelomeric regions that are adjacent to telomeres. Subtelomeres are actively involved in such chromosomal changes, and are therefore the most variable regions in the genome. The case of Caenorhabditis elegans in the context of changes of subtelomeric structures revealed by long-read sequencing is also discussed. Theoretical and methodological issues covered in this review will help to explore the mechanism of chromosome evolution by reconstruction of chromosomal ends in nature.
端粒内的 DNA 损伤修复受到抑制，以维持线性染色体的完整性，但修复的意外激活可能导致基因组不稳定。这篇综述提出了这样一个概念，即修复端粒内 DNA 损伤的机制有助于遗传变异和核型进化，而不是灾难。端粒的自发断裂可以被端粒酶修复，但在某些情况下，DNA 修复途径被激活，可能导致染色体重排或融合。由此产生的变化也可能影响与端粒相邻的亚端粒区域。亚端粒积极参与这种染色体变化，因此是基因组中最具变异性的区域。本文还讨论了秀丽隐杆线虫在长读测序揭示的亚端粒结构变化背景下的情况。本综述涵盖的理论和方法问题将有助于通过在自然界中重建染色体末端来探索染色体进化的机制。
