Division of Cancer and Genetics, School of Medicine, Cardiff University, Heath Park, Cardiff, CF14 4XN, UK
Philos Trans R Soc Lond B Biol Sci. 2018 Mar 5;373(1741). doi: 10.1098/rstb.2016.0437.
The terminal regions of eukaryotic chromosomes, composed of telomere repeat sequences and sub-telomeric sequences, represent some of the most variable and rapidly evolving regions of the genome. The sub-telomeric regions are characterized by segmentally duplicated repetitive DNA elements, interstitial telomere repeat sequences and families of variable genes. Sub-telomeric repeat sequence families are shared among multiple chromosome ends, often rendering detailed sequence characterization difficult. These regions are composed of constitutive heterochromatin and are subjected to high levels of meiotic recombination. Dysfunction within telomere repeat arrays, either due to disruption in the chromatin structure or because of telomere shortening, can lead to chromosomal fusion and the generation of large-scale genomic rearrangements across the genome. The dynamic nature of telomeric regions, therefore, provides functionally useful variation to create genetic diversity, but also provides a mechanism for rapid genomic evolution that can lead to reproductive isolation and speciation. This article is part of the theme issue 'Understanding diversity in telomere dynamics'.This article is part of the theme issue 'Understanding diversity in telomere dynamics'.
真核生物染色体的端区由端粒重复序列和亚端粒序列组成，是基因组中最具变异性和进化最快的区域之一。亚端粒区域的特征是片段重复的重复 DNA 元件、居间端粒重复序列和可变基因家族。亚端粒重复序列家族在多个染色体末端共享，通常使详细的序列特征变得困难。这些区域由组成型异染色质组成，并经历高水平的减数分裂重组。端粒重复序列阵列的功能障碍，要么是由于染色质结构的破坏，要么是由于端粒缩短，可能导致染色体融合和基因组范围内的大规模基因组重排。因此，端粒区域的动态性质为创造遗传多样性提供了功能上有用的变异，但也为快速的基因组进化提供了一种机制，这种进化可能导致生殖隔离和物种形成。本文是主题为“理解端粒动力学多样性”的特刊的一部分。
