Popitsch Niko, Huber Christian D, Buchumenski Ilana, Eisenberg Eli, Jantsch Michael, von Haeseler Arndt, Gallach Miguel
Oxford NIHR Biomedical Research Center, Wellcome Trust Center for Human Genetics, University of Oxford, Oxford, United Kingdom.
Institute of Molecular Biotechnology (IMBA), Vienna BioCenter (VBC), Vienna, Austria.
Genome Biol Evol. 2020 Apr 1;12(4):345-357. doi: 10.1093/gbe/evaa046.
In animals, the most common type of RNA editing is the deamination of adenosines (A) into inosines (I). Because inosines basepair with cytosines (C), they are interpreted as guanosines (G) by the cellular machinery and genomically encoded G alleles at edited sites mimic the function of edited RNAs. The contribution of this hardwiring effect on genome evolution remains obscure. We looked for population genomics signatures of adaptive evolution associated with A-to-I RNA edited sites in humans and Drosophila melanogaster. We found that single nucleotide polymorphisms at edited sites occur 3 (humans) to 15 times (Drosophila) more often than at unedited sites, the nucleotide G is virtually the unique alternative allele at edited sites and G alleles segregate at higher frequency at edited sites than at unedited sites. Our study reveals that a significant fraction of coding synonymous and nonsynonymous as well as silent and intergenic A-to-I RNA editing sites are likely adaptive in the distantly related human and Drosophila lineages.
在动物中，最常见的RNA编辑类型是腺苷（A）脱氨基变成肌苷（I）。由于肌苷与胞嘧啶（C）碱基配对，细胞机制将它们解读为鸟苷（G），并且编辑位点处基因组编码的G等位基因模拟了编辑后RNA的功能。这种硬连线效应在基因组进化中的作用仍不清楚。我们在人类和黑腹果蝇中寻找与A到I RNA编辑位点相关的适应性进化的群体基因组特征。我们发现，编辑位点处的单核苷酸多态性出现的频率比未编辑位点高3倍（人类）到15倍（果蝇），核苷酸G实际上是编辑位点处唯一的替代等位基因，并且G等位基因在编辑位点处的分离频率高于未编辑位点。我们的研究表明，在远缘相关的人类和果蝇谱系中，相当一部分编码同义、非同义以及沉默和基因间的A到I RNA编辑位点可能具有适应性。
