Department of Entomology and MOA Key Lab of Pest Monitoring and Green Management, College of Plant Protection, China Agricultural University, Beijing, 100193, China.
BMC Genomics. 2024 Aug 26;25(1):803. doi: 10.1186/s12864-024-10709-0.
Adenosine-to-inosine (A-to-I) RNA editing is a co-/post-transcriptional modification introducing A-to-G variations in RNAs. There is extensive discussion on whether the flexibility of RNA editing exerts a proteomic diversification role, or it just acts like hardwired mutations to correct the genomic allele. Eusocial insects evolved the ability to generate phenotypically differentiated individuals with the same genome, indicating the involvement of epigenetic/transcriptomic regulation.
We obtained the genomes of 104 Hymenoptera insects and the transcriptomes of representative species. Comparative genomic analysis was performed to parse the evolutionary trajectory of a regulatory Ile > Met auto-recoding site in Adar gene.
At genome level, the pre-editing Ile codon is conserved across a node containing all eusocial hymenopterans. At RNA level, the editing events are confirmed in representative species and shows considerable condition-specificity. Compared to random expectation, the editable Ile codon avoids genomic substitutions to Met or to uneditable Ile codons, but does not avoid mutations to other unrelated amino acids.
The flexibility of Adar auto-recoding site in Hymenoptera is selectively maintained, supporting the flexible RNA editing hypothesis. We proposed a new angle to view the adaptation of RNA editing, providing another layer to explain the great phenotypical plasticity of eusocial insects.
腺嘌呤到肌苷（A-to-I）的 RNA 编辑是一种共/转录后修饰，可在 RNA 中引入 A 到 G 的变异。人们广泛讨论了 RNA 编辑的灵活性是否发挥了蛋白质组多样化的作用，或者它只是像硬连线突变一样纠正基因组等位基因。真社会性昆虫进化出了产生具有相同基因组的表型分化个体的能力，这表明涉及表观遗传/转录组调控。
我们获得了 104 种膜翅目昆虫的基因组和代表性物种的转录组。进行了比较基因组分析，以解析 Adar 基因中调节性 Ile>Met 自动编码位点的进化轨迹。
在基因组水平上，包含所有真社会性膜翅目昆虫的节点中，前编辑的 Ile 密码子是保守的。在 RNA 水平上，在代表性物种中证实了编辑事件，并表现出相当大的条件特异性。与随机预期相比，可编辑的 Ile 密码子避免了基因组突变为 Met 或不可编辑的 Ile 密码子，但不避免突变为其他不相关的氨基酸。
膜翅目昆虫中 Adar 自动编码位点的灵活性是选择性保留的，支持灵活的 RNA 编辑假说。我们提出了一个新的角度来观察 RNA 编辑的适应，为真社会性昆虫的巨大表型可塑性提供了另一个解释层面。
