A nuclear mutation reversing a biased transmission of yeast mitochondrial DNA.
A nuclear mutation reversing a biased transmission of yeast mitochondrial DNA.
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逆转酵母线粒体 DNA 偏向传输的核突变。
DOI：
10.1093/genetics/128.2.241
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发表时间：
1991
期刊：
影响因子：
3.3
通讯作者：
Fangman,WL
中科院分区：
文献类型：
--
作者：
Zweifel,SG;Fangman,WL
在酿酒酵母的p-和p+细胞之间的高抑制交配中发生的p-线粒体DNA的高度偏传被认为是p- mtDNA复制优势的结果。一种核基因MGT1通过突变从合子克隆中发现了p+ mtDNA的位移。当一个单倍体亲本携带mgt1等位基因时，p- mtDNA的传递大大减少。当两个单倍体父母都携带mgt1等位基因时，p- mtDNA基本上从合子后代中消除。因此，在缺乏MGT1基因的情况下，在传递偏倚中存在一个开关；大多数合子克隆遗传的是p+ mtDNA而不是高抑制性p- mtDNA。与其在单倍体交配中的半显性行为相反，mgt1在二倍体交配中表现为隐性等位基因，因为当与mgt1 /mgt1高抑制性p-二倍体菌株交配时，mgt1 /mgt1二倍体中的p+基因组被有效地移位。我们发现，在MGT1 x MGT1交配衍生的无性系中，p+基因组可以与高抑制性p- mtDNA一起长时间保持。然而，正如预期的mgt1突变的隐性性质，这些p+基因组最终被消除。我们的研究表明，MGT1在高抑制p- mtdna和p+线粒体基因组之间的遗传竞争中起着至关重要的作用。MGT1基因产物可能是mtDNA复制系统的一个组成部分，该系统优先作用于在超抑制性mtDNA中发现的rep序列。
The highly biased transmission of p- mitochondrial DNA that occurs in hypersuppressive matings between p- and p+ cells of the yeast Saccharomyces cerevisiae is thought to be a consequence of the replication advantage of the p- mtDNA. A nuclear gene, MGT1, that is required for this displacement of p+ mtDNA from zygotic clones has been identified through mutation. When one haploid parent carries the mgt1 allele, transmission of p- mtDNA is substantially reduced. When both haploid parents carry the mgt1 allele, p- mtDNA is essentially eliminated from the zygotic progeny. Thus in the absence of the MGT1 gene there is a switch in the transmission bias; p+ mtDNA rather than the hypersuppressive p- mtDNA is inherited by most zygotic clones. In contrast to its semi-dominant behavior in haploid matings, mgt1 behaves as a recessive allele in diploid matings since the p+ genome in MGT1/mgt1 diploids is efficiently displaced when mated with a MGT1/mgt1 hypersuppressive p- diploid strain. We find that p+ genomes can be comaintained along with hypersuppressive p- mtDNA for extended periods in clonal lines derived from MGT1 x mgt1 matings. However, as expected from the recessive nature of the mgt1 mutation, these p+ genomes are eventually eliminated. Our work indicates that MGT1 plays a crucial role in the competition for inheritance between hypersuppressive p- mtDNAs and the p+ mitochondrial genome. The MGT1 gene product may be a component of a mtDNA replication system that acts preferentially at the rep sequences found in hypersuppressive mtDNAs.