Analysis of microsatellite mutations in the mitochondrial DNA of Saccharomyces cerevisiae.
Analysis of microsatellite mutations in the mitochondrial DNA of Saccharomyces cerevisiae.
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DOI：
10.1073/pnas.97.1.250
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发表时间：
2000-01
影响因子：
11.1
通讯作者：
E. Sia;Christine A. Butler;M. Dominska;P. Greenwell;T. Fox;T. Petes
中科院分区：
文献类型：
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作者：
E. Sia;Christine A. Butler;M. Dominska;P. Greenwell;T. Fox;T. Petes
在酿酒酵母的核基因组中，简单、重复的DNA序列(微卫星)的突变率远远高于非重复序列。这些突变大多是重复单位的缺失或增加。酵母线粒体基因组也含有许多微卫星。为了检测这些序列的稳定性，我们构建了一个报告基因(arg8(M))，该基因包含了编码序列中多聚(AT)或多聚(GT)区域的框外插入。构建了线粒体基因组中插入该报告基因的酵母菌株。使用这些菌株，我们发现聚(GT)束比聚(AT)束更不稳定，而且改变通常涉及重复单位的删除而不是增加。相反，在核基因组中，聚(GT)和聚(AT)区具有相似的稳定性，改变通常涉及增加而不是缺失。多聚(GT)束在二倍体细胞的线粒体中比单倍体细胞中更稳定。此外，msh1突变破坏了线粒体基因组中多聚(GT)区域的稳定。
In the nuclear genome of Saccharomyces cerevisiae, simple, repetitive DNA sequences (microsatellites) mutate at rates much higher than nonrepetitive sequences. Most of these mutations are deletions or additions of repeat units. The yeast mitochondrial genome also contains many microsatellites. To examine the stability of these sequences, we constructed a reporter gene (arg8(m)) containing out-of-frame insertions of either poly(AT) or poly(GT) tracts within the coding sequence. Yeast strains with this reporter gene inserted within the mitochondrial genome were constructed. Using these strains, we showed that poly(GT) tracts were considerably less stable than poly(AT) tracts and that alterations usually involved deletions rather than additions of repeat units. In contrast, in the nuclear genome, poly(GT) and poly(AT) tracts had similar stabilities, and alterations usually involved additions rather than deletions. Poly(GT) tracts were more stable in the mitochondria of diploid cells than in haploids. In addition, an msh1 mutation destabilized poly(GT) tracts in the mitochondrial genome.