CONSERVED NUCLEOPROTEIN STRUCTURE AT THE ENDS OF VERTEBRATE AND INVERTEBRATE CHROMOSOMES
CONSERVED NUCLEOPROTEIN STRUCTURE AT THE ENDS OF VERTEBRATE AND INVERTEBRATE CHROMOSOMES
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DOI：
10.1073/pnas.92.6.2393
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发表时间：
1995-03-14
影响因子：
11.1
通讯作者：
LANGMORE, JP
中科院分区：
文献类型：
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作者：
LEJNINE, S;MAKAROV, VL;LANGMORE, JP
真核细胞染色体终止于端粒，端粒是一种对染色体稳定性至关重要的核蛋白结构。脊椎动物端粒由末端DNA序列（TTAGGG）（n）组成，在大鼠中主要组织成间隔157 bp的核小体。为了检验其他动物的端粒具有核小体的假设，我们比较了来自八种脊椎动物组织和细胞培养物的端粒，以及来自无脊椎动物的两种组织。所有端粒都具有占基因组的0.01-0.2%的大量（TTAGGG）（n）束。所有的端粒都很长（20-100 kb），除了海胆，人类和一些鸡的染色体，长度为3-10 kb。所有的动物端粒都含有核小体阵列，与最初的假设一致。端粒重复长度从151到205 bp不等，似乎与端粒大小、核小体间距的规律性、物种或分化状态无关，但令人惊讶的是与同一细胞内大量染色质的重复相关。端粒核小体始终比散装核小体小约30 bp。因此，动物端粒具有高度保守的序列和具有细胞特异性结构的异常短的核小体。
Eukaryotic chromosomes terminate with telomeres, nucleoprotein structures that are essential for chromosome stability. Vertebrate telomeres consist of terminal DNA tracts of sequence (TTAGGG)(n), which in rat are predominantly organized into nucleosomes regularly spaced by 157 bp. To test the hypothesis that telomeres of other animals have nucleosomes, we compared telomeres from eight vertebrate tissues and cell cultures, as well as two tissues from an invertebrate, All telomeres have substantial tracts of (TTAGGG)(n) comprising 0.01-0.2% of the genome. All telomeres are long (20-100 kb), except for those of sea urchin, human, and some chicken chromosomes, which are 3-10 kb in length. All of the animal telomeres contained nucleosome arrays, consistent with the original hypothesis. The telomere repeat lengths vary from 151 to 205 bp, seemingly uncorrelated with telomere size, regularity of nucleosome spacing, species, or state of differentiation but surprisingly correlated with the repeat of bulk chromatin within the same cells. The telomere nucleosomes were consistently approximate to 30 bp smaller than bulk nucleosomes. Thus, animal telomeres have highly conserved sequences and unusually short nucleosomes with cell-sepcific structure.