Extensive allelic variation and ultrashort telomeres in senescent human cells
Extensive allelic variation and ultrashort telomeres in senescent human cells
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DOI：
10.1038/ng1084
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发表时间：
2003-02-01
期刊：
影响因子：
30.8
通讯作者：
Kipling, D
中科院分区：
文献类型：
--
作者：
Baird, DM;Rowson, J;Kipling, D
通过限制大多数体细胞的增殖寿命，端粒侵蚀代表了肿瘤抑制的先天机制（1），并可能导致年龄相关疾病（2）。由于目前的方法无法详细分析端粒的动态变化，对端粒缩短与复制性衰老之间的联系的详细了解受到严重阻碍。在这里，我们描述了单个端粒长度分析（STELA），一种基于PCR的方法，可以准确地测量来自单个染色体的端粒长度的全谱。成纤维细胞中人XpYp端粒的STELA分析鉴定了端粒生物学的几个特征。我们观察到正常成纤维细胞中端粒的双峰分布，这些分布导致高达6.5 kb的等位基因间的差异，这表明在整个发育过程中保持合子端粒长度的意外大规模差异。大多数端粒以逐渐的方式缩短，与通过末端复制的简单损失一致，并且侵蚀的速率与等位基因的大小无关。叠加在此之上的是偶然的、更实质性的长度变化，这可能是额外突变机制的结果。值得注意的是，一些等位基因在衰老时显示TTAGGG重复序列几乎完全丢失。
By imposing a limit on the proliferative lifespan of most somatic cells, telomere erosion represents an innate mechanism for tumor suppression(1) and may contribute to age-related disease(2). A detailed understanding of the pathways that link shortened telomeres to replicative senescence has been severely hindered by the inability of current methods to analyze telomere dynamics in detail. Here we describe single telomere length analysis (STELA), a PCR-based approach that accurately measures the full spectrum of telomere lengths from individual chromosomes. STELA analysis of human XpYp telomeres in fibroblasts identifies several features of telomere biology. We observe bimodal distributions of telomeres in normal fibroblasts; these distributions result from inter-allelic differences of up to 6.5 kb, indicating that unexpectedly large-scale differences in zygotic telomere length are maintained throughout development. Most telomeres shorten in a gradual fashion consistent with simple losses through end replication, and the rates of erosion are independent of allele size. Superimposed on this are occasional, more substantial changes in length, which may be the consequence of additional mutational mechanisms. Notably, some alleles show almost complete loss of TTAGGG repeats at senescence.