无齿稻蝗和黄翅踵蝗线粒体基因组与系统发育分析

Complete Mitochondrial Genomes and Phylogenetic Analysis of Oxya adentata and Pternoscirta caliginosa

为了研究无齿稻蝗和黄翅踵蝗在蝗总科的系统发育地位,本研究采用基于长PCR的二次PCR方法对这两种蝗虫的线粒体基因组进行了测定和系统发育分析。结构显示：无齿稻蝗和黄翅踵蝗线粒体基因组全长分别是15 447 bp和15 598 bp,均含有典型的37个基因以及一个控制区,基因排序和数量与其他已知近缘昆虫相同;线粒体基因组A＋T含量分别是75.4%、75.4%。两种蝗虫的蛋白质编码基因中均是除了COX1的起始密码子是ACC,其他都是典型的起始密码子ATN;所有蛋白质编码基因的终止密码子都是典型的TAA或TAG;两种蝗虫t RNA基因中,21个能形成三叶草结构,只有trn^（SAGN）缺少DHU臂;黄翅踵蝗控制区的N链出现一个tRNA-like的结构。由两个外群和24个蝗总科物种构建的系统树结果显示无齿稻蝗与小稻蝗为姐妹群,黄翅踵蝗与飞蝗属和车蝗属与小车蝗属组成的分支为姐妹群。

In order to explore the phylogenetic position of Oxya adentata and Pternoscirta caliginosa, the long-PCR and sub-PCR were used to determine and analyze the complete mitochondrial genomes of O. adentata and P.caliginosa. The results revealed that O. adentata and P. caliginosa were 15 447 bp and 15 598 bp in size, respectively,and both contained 37 typical genes and a control region. The order and number of genes in H. tonkinensis and P.caliginosa was consistent with the order of other closely related species. The A ＋T content in mitogenomes were75.4% and 75.4%, respectively. Most protein-coding genes started with typical ATN codon except for COX1, which both started with ACC codon instead, while all PCGs used complete stop codons（TAA and TAG）. Most tRNA genes could form typical secondary structures except trn S^（AGN）, which had an absence of the DHU arm. An unusual feature of the P. caliginosa mitogenome was the presence of t RNA-like structure on the N-strand in control region. In addition,24 Acridoidea species and 2 out-group taxa were used to construct the phylogenetic tree to further validate the mitogenome of O. adentata and P. caliginosa. The result showed that O. adentata was sister group to Oxya. P.caliginosa was sister group to the clade of Locusta and the branch of Gastrimargus and Oedaleus.