Zhdanova N S, Rubtsov N B, Minina Iu M
Genetika. 2007 Jul;43(7):873-86.
The review considers data on the composition, organization, and functional significance of terminal regions in mammalian chromosomes, including telomeres and subtelomeric regions. Because of specific structure, features of DNA replication, and characteristic localization in somatic and meiotic cells, these regions are hot spots for many events associated with genome functioning in mammals. Instability of these regions is of special interest. Evidence suggesting that instability of chromosomal regions containing telomeric DNA is a factor of chromosome evolution is discussed. The association of size and structure of telomeric regions with replicative aging and cell immortalization is considered. The review deals in detail with classical and alternative mechanisms of telomere size control, the significance of changes in telomeric region length in ontogeny, oncotransformation, and evolution. The issues related to telomere destabilization and the role of this process in chromosome rearrangement formation and chromosome evolution are discussed. The origin of telomere repeats in interstitial chromosome sites, including regions of evolutionary fusions-fissions is given special consideration. The possible role of ribosomal repeats and mechanisms similar to ALT (alternative lengthening of telomeres) in telomere reorganization in some taxa are discussed.
本综述探讨了哺乳动物染色体末端区域（包括端粒和亚端粒区域）的组成、组织及功能意义相关的数据。由于这些区域具有特定的结构、DNA复制特点以及在体细胞和减数分裂细胞中的特征定位，它们是许多与哺乳动物基因组功能相关事件的热点。这些区域的不稳定性备受关注。文中讨论了表明含有端粒DNA的染色体区域不稳定性是染色体进化因素的证据。还考虑了端粒区域的大小和结构与复制性衰老及细胞永生化的关联。本综述详细阐述了端粒大小控制的经典和替代机制、端粒区域长度变化在个体发育、肿瘤转化及进化中的意义。讨论了与端粒不稳定相关的问题以及该过程在染色体重排形成和染色体进化中的作用。特别考虑了间质染色体位点中端粒重复序列的起源，包括进化融合 - 裂变区域。还讨论了核糖体重复序列在某些分类群中端粒重组中可能发挥的作用以及类似于端粒替代延长（ALT）的机制。
