He Wei, Li Tingting, Wang Liyang, Wu Hongxuan, Wang Jie, Zhou Qiang
State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou 510275, China.
Insects. 2025 May 20;16(5):543. doi: 10.3390/insects16050543.
This study reports the first complete mitochondrial genomes of three egg parasitoid wasps parasitizing -, , and . Genome sizes ranged from 15,429 to 15,889 bp, with all three mitogenomes displaying strong A + T bias, standard gene content, and characteristic strand asymmetries. While and exhibited conserved gene orders, extensive gene rearrangements, including multiple inversions in both protein-coding genes (PCGs) and tRNAs, were observed in . Codon usage analyses revealed a preference for codons ending in A or U. The non-synonymous (Ka) to synonymous (Ks) substitution ratio analysis identified signs of positive selection in multiple PCGs, particularly in , , and , suggesting possible adaptive evolution related to host-searching behavior. Secondary structure analyses showed the loss of in all species, while and lacked the DHU arm, indicating possible derived traits in Mymaridae. Phylogenetic analysis was the first time to describe the relationship of the genus within Mymaridae from the perspective of 13 protein genes. Furthermore, the grouping of ( + ) + was supporting the distinct evolutionary lineage of . This work provides new molecular resources and phylogenetic insight for Chalcidoidea, with implications for parasitoid evolution and biological control strategies.
本研究报告了三种寄生在[寄主1]、[寄主2]和[寄主3]上的卵寄生蜂的首个完整线粒体基因组。基因组大小在15429至15889碱基对之间，所有三个线粒体基因组均表现出强烈的A+T偏好、标准的基因组成以及特征性的链不对称性。虽然[物种1]和[物种2]表现出保守的基因顺序，但在[物种3]中观察到了广泛的基因重排，包括蛋白质编码基因（PCGs）和tRNA中的多次倒位。密码子使用分析显示偏好以A或U结尾的密码子。非同义（Ka）与同义（Ks）替换率分析确定了多个PCGs中存在正选择的迹象，特别是在[基因1]、[基因2]和[基因3]中，表明可能与寄主搜索行为相关的适应性进化。二级结构分析表明，所有[物种组]物种中均缺失了[结构元件]，而[物种1]和[物种2]缺乏DHU臂，这表明缨小蜂科可能存在衍生特征。系统发育分析首次从13个蛋白质基因的角度描述了缨小蜂科内[属名]的关系。此外，（[物种1]+[物种2]）+[物种3]的分组支持了[物种3]独特的进化谱系。这项工作为小蜂总科提供了新的分子资源和系统发育见解，对寄生蜂的进化和生物防治策略具有重要意义。
