MSH1 is required for maintenance of the low mutation rates in plant mitochondrial and plastid genomes

文献类型： 外文期刊

第一作者： Wu, Zhiqiang

作者： Wu, Zhiqiang;Wu, Zhiqiang;Waneka, Gus;Broz, Amanda K.;King, Connor R.;Sloan, Daniel B.

作者机构：

关键词： duplex sequencing; mutation rate; plant mitochondria; chloroplast; organelle genomes

期刊名称：PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA （ 影响因子：11.205； 五年影响因子：12.291 ）

ISSN： 0027-8424

年卷期： 2020 年 117 卷 28 期

页码：

收录情况： SCI

摘要： Mitochondrial and plastid genomes in land plants exhibit some of the slowest rates of sequence evolution observed in any eukaryotic genome, suggesting an exceptional ability to prevent or correct mutations. However, the mechanisms responsible for this extreme fidelity remain unclear. We tested seven candidate genes involved in cytoplasmic DNA replication, recombination, and repair (POLIA, POLIB, MSH1, RECA3, UNG, FPG, and OGG1) for effects on mutation rates in the model angiosperm Arabidopsis thaliana by applying a highly accurate DNA sequencing technique (duplex sequencing) that can detect newly arisen mitochondrial and plastid mutations even at low heteroplasmic frequencies. We find that disrupting MSH1 (but not the other candidate genes) leads to massive increases in the frequency of point mutations and small indels and changes to the mutation spectrum in mitochondrial and plastid DNA. We also used droplet digital PCR to show transmission of de novo heteroplasmies across generations in msh1 mutants, confirming a contribution to heritable mutation rates. This dual-targeted gene is part of an enig-matic lineage within the mutS mismatch repair family that we find is also present outside of green plants in multiple eukaryotic groups (stramenopiles, alveolates, haptophytes, and cryptomonads), as well as certain bacteria and viruses. MSH1 has previously been shown to limit ectopic recombination in plant cytoplasmic genomes. Our results point to a broader role in recognition and correction of errors in plant mitochondrial and plastid DNA sequence, leading to greatly suppressed mutation rates perhaps via initiation of double -stranded breaks and repair pathways based on faithful homologous recombination.

分类号：

  • 相关文献
作者其他论文 更多>>

微信小程序