CTG triplet repeats from the myotonic dystrophy gene are expanded in Escherichia coli distal to the replication origin as a single large event.
CTG triplet repeats from the myotonic dystrophy gene are expanded in Escherichia coli distal to the replication origin as a single large event.
复制标题
来自强直性营养不良基因的 CTG 三联体重复在复制起点远端的大肠杆菌中作为单个大事件进行扩展。
DOI：
10.1006/jmbi.1996.0266
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发表时间：
1996
期刊：
影响因子：
--
通讯作者：
Wells,RD
中科院分区：
文献类型：
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作者：
Kang,S;Ohshima,K;Jaworski,A;Wells,RD
CTG和CGG三核苷酸重复序列的扩增和收缩与几种遗传性遗传疾病有关。我们建立了一个系统来研究大肠杆菌中三联体重复序列的扩增，以阐明其分子机制。使用中断CTA三联体序列作为CTG道内的位置标记对扩展区域的分析揭示，大CTG重复的扩展是一个事件，而不是多个小扩展的累积，并且扩展更频繁地发生在远离复制起点的区域中。此外，我们发现，中断的损失增加了扩展频率。因此，遗传性疾病中大三联体重复序列的不稳定性是通过与某些散发性癌症和遗传性非息肉病性结直肠癌的错配修复系统缺陷引起的微卫星序列不稳定性不同的机制发生的。
The expansion and contraction of CTG and CGG trinucleotide repeat sequences have been associated with several heritable genetic diseases. We developed a system for investigating the expansion of triplet repeat sequences inEscherichia coliin order to elucidate molecular mechanisms. Analysis of expanded regions using the interrupting CTA triplet sequence as a location marker within the CTG tract revealed that the expansion of large CTG repeats is one event rather than an accumulation of multiple small expansions and that the expansions occur more frequently in the region distal from the replication origin. Also, we showed that a loss of interruptions increases the expansion frequency. Thus, the instability of large triplet repeats in hereditary diseases occurs by a mechanism different from the instability in microsatellite sequences caused by defects in mismatch repair systems for certain sporadic cancers and hereditary non-polyposis colorectal cancers.