Conservation and characterization of unique porcine interstitial telomeric sequences
Conservation and characterization of unique porcine interstitial telomeric sequences
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DOI：
10.1007/s11427-012-4420-x
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发表时间：
2012-12-01
影响因子：
9.1
通讯作者：
Liu Lin
中科院分区：
文献类型：
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作者：
Ji GuangZhen;Liu Kai;Liu Lin
端粒由TTAGGG重复序列组成，位于染色体末端。端粒保护哺乳动物（包括小鼠和人类）的染色体不稳定。重复TTAGGG序列也存在于染色体内位点，在那里它们被命名为间质端粒序列（ITS）。异常ITS与染色体不稳定性有关，并在癌细胞中发现。有趣的是，在猪中，脊椎动物端粒序列TTAGGG（vITS）也位于染色体6的着丝粒区域，除了所有染色体的末端。令人惊讶的是，我们发现，植物端粒序列，TTTAGGG（bITS），也本地化与vITS在猪6号染色体的着丝粒区域使用端粒荧光原位杂交（FISH）和几个物种之间的比较。此外，vITS的平均长度与末端端粒（TTS）的平均长度高度相关。此外，猪ITS显示端粒双联体的高发生率，表明猪ITS可能是不稳定和动态的。总之，我们的研究结果表明，猪细胞保持保守的端粒序列，发现在ITS从植物和其他脊椎动物。深入了解猪ITSs的功能和调控，可能为猪的进化和染色体不稳定性提供新的线索。
Telomeres are composed of TTAGGG repeats and located at the ends of chromosomes. Telomeres protect chromosomes from instability in mammals, including mice and humans. Repetitive TTAGGG sequences are also found at intrachromosomal sites, where they are named as interstitial telomeric sequences (ITSs). Aberrant ITSs are implicated in chromosomal instability and found in cancer cells. Interestingly, in pigs, vertebrate telomere sequences TTAGGG (vITSs) are also localized at the centromeric region of chromosome 6, in addition to the end of all chromosomes. Surprisingly, we found that botanic telomere sequences, TTTAGGG (bITSs), also localize with vITSs at the centromeric regions of pig chromosome 6 using telomere fluorescence in situ hybridization (FISH) and by comparisons between several species. Furthermore, the average lengths of vITSs are highly correlated with those of the terminal telomeres (TTS). Also, pig ITSs show a high incidence of telomere doublets, suggesting that pig ITSs might be unstable and dynamic. Together, our results show that pig cells maintain the conserved telomere sequences that are found at the ITSs from of plants and other vertebrates. Further understanding of the function and regulation of pig ITSs may provide new clues for evolution and chromosomal instability.