MECHANISMS UNDERLYING TELOMERE REPEAT TURNOVER, REVEALED BY HYPERVARIABLE VARIANT REPEAT DISTRIBUTION PATTERNS IN THE HUMAN XP/YP TELOMERE
MECHANISMS UNDERLYING TELOMERE REPEAT TURNOVER, REVEALED BY HYPERVARIABLE VARIANT REPEAT DISTRIBUTION PATTERNS IN THE HUMAN XP/YP TELOMERE
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DOI：
10.1002/j.1460-2075.1995.tb00227.x
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发表时间：
1995-11-01
期刊：
影响因子：
11.4
通讯作者：
ROYLE, NJ
中科院分区：
文献类型：
--
作者：
BAIRD, DM;JEFFREYS, AJ;ROYLE, NJ
与人类XP/Yp端粒相邻的序列表现出很高的碱基替换多态频率，加上几乎完全的连锁不平衡，只产生了几个不同的单倍型，这种序列差异已被用来开发一个基于PCR的系统，用于定位端粒重复序列阵列近端的端粒(TTAGGG)和变异重复序列(TGAGGG和TCAGGG)的分布，这些重复序列的分布非常可变，几乎所有的XP/YP端粒都不同，表明有很高的突变率。一些与同一侧翼单倍型相关的端粒图谱显示出相似之处，鉴定了共享最近共同祖先的端粒亚群，XP/YP端粒近端重复序列快速更替的机制包括等位基因内过程，如复制过程中的滑移，等位基因间交换可能偶尔发生，但端粒酶活性可能只在最近定位的端粒和变体重复序列的种系更替中起次要作用。
Sequences immediately adjacent to the human Xp/Yp telomere exhibit a high frequency of base substitutional polymorphisms, together with almost complete linkage disequilibrium, to create only a few diverged haplotypes, This sequence divergence has been used to develop a PCR-based system for mapping the distribution of the telomere (TTAGGG) and variant repeats (TGAGGG and TCAGGG) at the proximal end of the telomere repeat array, The distribution of these repeats is extremely variable, Almost all Xp/Yp telomeres are different, indicating a high mutation rate. Some telomere maps associated with the same flanking haplotype show similarities, identifying subsets of telomeres that share a recent common ancestry, Mechanisms underlying the rapid turnover of repeats at the proximal end of the Xp/Yp telomere include intraallelic processes, such as slippage during replication, Inter-allelic exchanges may occur occasionally, but telomerase activity probably plays only a minor role in the germline turnover of proximally located telomere and variant repeats.