PDF(Pubmed)
Abstract：
Although A-to-I RNA editing leads to similar effects to A-to-G DNA mutation, nonsynonymous RNA editing (recoding) is believed to confer its adaptiveness by \'epigenetically\' regulating proteomic diversity in a temporospatial manner, avoiding the pleiotropic effect of genomic mutations. Recent discoveries on the evolutionary trajectory of Ser>Gly auto-editing site in insect Adar gene demonstrated a selective advantage to having an editable codon compared to uneditable ones. However, apart from pure observations, quantitative approaches for justifying the adaptiveness of individual RNA editing sites are still lacking. We performed a comparative genomic analysis on 113 Diptera species, focusing on the Adar Ser>Gly auto-recoding site in Drosophila. We only found one species having a derived Gly at the corresponding site, and this occurrence was significantly lower than genome-wide random expectation. This suggests that the Adar Ser>Gly site is unlikely to be genomically replaced with G during evolution, and thus indicating the advantage of editable status over hardwired genomic alleles. Similar trends were observed for the conserved Ile>Met recoding in gene Syt1. In the light of evolution, we established a comparative genomic approach for quantitatively justifying the adaptiveness of individual editing sites. Priority should be given to such adaptive editing sites in future functional studies.
摘要：
尽管A到IRNA编辑导致与A到GDNA突变类似的效果，非同义RNA编辑（重新编码）被认为通过以时空方式调节蛋白质组多样性而赋予其适应性，避免基因组突变的多效性效应。昆虫Adar基因中Ser>Gly自动编辑位点的进化轨迹的最新发现表明，与不可编辑的密码子相比，具有可编辑的密码子具有选择性优势。然而,除了纯粹的观察，仍然缺乏证明单个RNA编辑位点适应性的定量方法。我们对113种双翅目进行了比较基因组分析，专注于果蝇的AdarSer>Gly自动重新编码位点。我们只在相应的地点发现了一个具有衍生Gly的物种，这种情况明显低于全基因组随机预期。这表明AdarSer>Gly位点在进化过程中不太可能被G基因组取代，从而表明可编辑状态优于硬连线基因组等位基因。对于Syt1基因中保守的Ile>Met重新编码观察到类似的趋势。从进化的角度来看，我们建立了一种比较基因组方法，用于定量证明单个编辑位点的适应性。在未来的功能研究中，应优先考虑此类自适应编辑站点。
