State Key Laboratory of Rice Biology and Ministry of Agriculture Key Lab of Molecular Biology of Crop Pathogens and Insects, Institute of Insect Sciences, Zhejiang University, Hangzhou 310058, China.
Department of Terrestrial Zoology, Naturalis Biodiversity Center, Postbus 9517, RA, 2300 Leiden, the Netherlands.
Int J Biol Macromol. 2019 Feb 15;123:1189-1196. doi: 10.1016/j.ijbiomac.2018.11.017. Epub 2018 Nov 5.
The Symphyta has long been recognized as a paraphyletic grade forming the base of the remaining Hymenopteran, and the superfamily relationships within Symphyta remain controversial. Here, the first two representative mitochondrial genomes from the superfamily Siricoidea and Xiphydrioidea (Hymenoptera: Symphyta) are obtained using next-generation sequencing. The complete mitochondrial genome of Xiphydria sp. is 16,482 bp long with an A + T content of 84.18% while the incomplete one of Tremex columba is 16,847 bp long and A + T content is 81.69%. All 37 typical mitochondrial genes are possessed in both species. The secondary structure of tRNAs and rRNAs for both species are successfully predicted. Compared with the ancestral organization, seven and five tRNA genes are rearranged in mitochondrial genomes of Tremex and Xiphydria, respectively, which are the most rearrangement events within Symphyta. The rearrangement patterns in Tremex and Xiphydria present in this study are all novel to the Symphyta. Phylogenetic relationships among the major lineages of Symphyta are reconstructed using mitochondrial genomes. Both maximum likelihood and Bayesian inference analyses highly support Symphyta is a paraphyletic grade, Xyeloidea + (Tenthredinoidea + (Pamphilioidea + (Xiphydrioidea + (Cephoidea + (Orussoidea + Apocrita))))).
多食亚目（膜翅目）长期以来被认为是一个并系阶元，构成了其余膜翅目昆虫的基部，多食亚目内部的超家族关系仍然存在争议。在这里，我们通过下一代测序获得了来自 Siricoidea 和 Xiphydrioidea 超家族（膜翅目：多食亚目）的两个代表的线粒体基因组。Xiphydria sp. 的完整线粒体基因组长 16482bp，A+T 含量为 84.18%，而不完全的 Tremex columba 线粒体基因组长 16847bp，A+T 含量为 81.69%。两种生物都拥有所有 37 个典型的线粒体基因。两种生物的 tRNA 和 rRNA 的二级结构都成功预测。与祖先组织相比，Tremex 和 Xiphydria 的线粒体基因组中分别有 7 个和 5 个 tRNA 基因发生重排，这是在膜翅目内发生的最多重排事件。在本研究中，Tremex 和 Xiphydria 中发现的重排模式在多食亚目内都是新颖的。利用线粒体基因组重建了多食亚目主要分支的系统发育关系。最大似然法和贝叶斯推断分析都高度支持多食亚目是一个并系阶元，即 Xyeloidea+（Tenthredinoidea+（Pamphilioidea+（Xiphydrioidea+（Cephoidea+（Orussoidea+（Apocrita））））。
