Genome defense against integrated organellar DNA fragments from plastids into plant nuclear genomes through DNA methylation
Genome defense against integrated organellar DNA fragments from plastids into plant nuclear genomes through DNA methylation
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DOI：
10.1038/s41598-019-38607-6
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发表时间：
2019-02
影响因子：
4.6
通讯作者：
Takanori Yoshida;Hazuka Y. Furihata;T. To;T. Kakutani;A. Kawabe
中科院分区：
文献类型：
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作者：
Takanori Yoshida;Hazuka Y. Furihata;T. To;T. Kakutani;A. Kawabe
核基因组总是面临着外源DNA和转座因子等内源寄生物的插入和整合对自身的修饰。共生细胞器基因组与宿主细胞核基因组之间也存在大量的整合。这种整合在共生进化过程中可能是一种有益的突变，而其中大多数对当前基因组的稳定性或多或少有有害影响。在这里，我们报告的模式DNA取代和甲基化的细胞器DNA片段整合到植物细胞核基因组中。对17种植物的基因组分析表明，它们具有同源性依赖的DNA替换偏向性。这些序列中的一定数量在核基因组中是DNA甲基化的。DNA甲基化的强度在整合到核基因组后也随着相对进化时间的增加而衰减。表观遗传突变体的甲基化组数据表明，核基因组中细胞器DNA片段的甲基化主要依赖于甲基化维持机制，而其他机制也可能影响DNA甲基化水平。细胞器DNA片段的甲基化可能有助于维持共生细胞器及其宿主基因组的稳定性和进化动力学。
Nuclear genomes are always faced with the modification of themselves by insertions and integrations of foreign DNAs and intrinsic parasites such as transposable elements. There is also substantial number of integrations from symbiotic organellar genomes to their host nuclear genomes. Such integration might have acted as a beneficial mutation during the evolution of symbiosis, while most of them have more or less deleterious effects on the stability of current genomes. Here we report the pattern of DNA substitution and methylation on organellar DNA fragments integrated from plastid into plant nuclear genomes. The genome analyses of 17 plants show homology–dependent DNA substitution bias. A certain number of these sequences are DNA methylated in the nuclear genome. The intensity of DNA methylation also decays according to the increase of relative evolutionary times after being integrated into nuclear genomes. The methylome data of epigenetic mutants shows that the DNA methylation of organellar DNA fragments in nuclear genomes are mainly dependent on the methylation maintenance machinery, while other mechanisms may also affect on the DNA methylation level. The DNA methylation on organellar DNA fragments may contribute to maintaining the genome stability and evolutionary dynamics of symbiotic organellar and their host’s genomes.