Effects of ploidy, growth conditions and the mitochondrial nucleoid-associated protein Ilv5p on the rate of mutation of mitochondrial DNA in Saccharomyces cerevisiae.
Effects of ploidy, growth conditions and the mitochondrial nucleoid-associated protein Ilv5p on the rate of mutation of mitochondrial DNA in Saccharomyces cerevisiae.
复制标题
倍性、生长条件和线粒体核相关蛋白 Ilv5p 对酿酒酵母线粒体 DNA 突变率的影响。
DOI：
10.1007/s00294-003-0420-5
复制
发表时间：
2003
期刊：
影响因子：
2.5
通讯作者：
Sia,ElaineAyres
中科院分区：
文献类型：
--
作者：
Sia,ReyAL;Urbonas,BethL;Sia,ElaineAyres
微卫星或简单重复序列在真核生物基因组和酿酒酵母线粒体基因组中大量存在。这些序列的变化速率明显高于同等大小的非重复序列。二倍体酵母细胞线粒体微卫星的稳定性是等基因单倍体细胞的近100倍。我们能够证明，这种影响可能是由于倍性本身，而不是由于特定交配类型的基因表达。此外，我们证明氨基酸饥饿会影响线粒体DNA的组织及其在芽中的分离。我们还测试了氨基酸饥饿对单倍体和二倍体酵母细胞线粒体DNA拷贝数和突变率的影响。与缺乏氨基酸的细胞相比，在富培养基中生长的酵母细胞线粒体DNA含量较低，线粒体DNA移码突变和点突变的突变率也相应较高。这些影响似乎依赖于线粒体核相关蛋白Ilv5p。
Microsatellites, or simple repetitive sequences, are abundant in eukaryotic genomes and in the mitochondrial genome ofSaccharomyces cerevisiae. These sequences alter at rates significantly higher than non-repetitive sequences of comparable size. The stability of a mitochondrial microsatellite is nearly 100-fold greater in diploid yeast cells than in isogenic haploid cells. We were able to demonstrate that this effect is likely due to ploidy alone, rather than mating-type-specific gene expression. In addition, we demonstrated that amino acid starvation affects the organization of the mitochondrial DNA and its segregation into the bud. We also tested the effect of amino acid starvation on the copy number and the mutation rate of mitochondrial DNA in both haploid and diploid yeast cells. Yeast cells grown in rich medium have a lower mitochondrial DNA content than cells starved for amino acids and have a correspondingly higher mutation rate for both frameshift mutations and point mutations in mitochondrial DNA. These effects appear to be dependent on the mitochondrial nucleoid-associated protein Ilv5p.