Capture of retrotransposon DNA at the sites of chromosomal double-strand breaks
Capture of retrotransposon DNA at the sites of chromosomal double-strand breaks
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DOI：
10.1038/383644a0
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发表时间：
1996-10-17
期刊：
影响因子：
64.8
通讯作者：
Haber, JE
中科院分区：
文献类型：
--
作者：
Moore, JK;Haber, JE
通过表达切割交配型（MAT）位点的位点特异性HO内切酶，可以在确定的位置研究酿酒酵母中断裂染色体的非同源修复。当同源重组被阻止时，大多数双链断裂通过与在哺乳动物细胞中观察到的类似的非同源末端连接来修复。大约1%的非同源修复事件是例外的，在HO切割位点内“捕获”了大约100个碱基对的DNA。在每种情况下，插入来自酵母的反转录转座子Ty 1元件。其中4个含有R-U 5区域，这是Ty 1信使RNA转化为互补DNA的第一部分。在双链断裂位点捕获cDNA片段可能解释了假基因和长短散布序列（LINES和西内斯）插入哺乳动物基因组许多位置的方式。
NON-HOMOLOGOUS repair of broken chromosomes in Saccharomyces cerevisiae san be studied at a defined location by expressing the site-specific HO endonuclease that cuts the mating-type (MAT) locus. When homologous recombination is prevented, most double-strand breaks are repaired by non-homologous end-joinings similar to those observed in mammalian cells. About 1% of non-homologous repair events were exceptional, having 'captured' approximately 100 base pairs of DNA within the HO cleavage site. In each case, the insertion came from yeast's retrotransposon Ty1 element. Four of the five contained the R-U5 region, which is the first part of Ty1 messenger RNA to be converted to complementary DNA. The capture of cDNA fragments at fhe sites of double-strand breaks may account for the way that pseudogenes and long and short interspersed sequences (LINES and SINES) have been inserted at many locations in the mammalian genome.