National Institute of Agrobiological Sciences, Tsukuba, Ibaraki 305-8634, Japan.
Genome. 2012 Mar;55(3):222-33. doi: 10.1139/g2012-007. Epub 2012 Feb 29.
Webspinners (order Embioptera) are polyneopteran insects characterized by enlarged foretarsi with silk glands, whose silk is used to produce galleries in which the insects live gregariously. The phylogenetic position of webspinners has been debated. In the present study, an almost complete mitochondrial DNA (mtDNA) sequence of Embioptera is reported for the first time. The mtDNA of a webspinner, Aposthonia japonica , has the 13 protein-coding genes (PCGs) generally found in metazoan mtDNA sequences. There is a translocation of a large region including atp6, atp8, cox3, nad3, and nad5 as well as a duplication of the 12S rRNA gene. The rearrangement does not seem to affect nucleotide composition, although amino acid composition in some parts of the mtDNA is biased compared with other Polyneoptera species. Based on phylogenetic analyses using nucleotide sequences of all PCGs concatenated with two rRNA genes and the amino acid sequences of all PCGs, A. japonica is sister to Verophasmatodea, a suborder of typical stick and leaf insects.
缨翅目昆虫是一类多具翅的昆虫，其特征为前跗节变大且具丝腺，其丝用于构建群居生活的栖所。缨翅目昆虫的系统发育位置一直存在争议。本研究首次报道了缨翅目昆虫（Aposthonia japonica）的近乎完整的线粒体 DNA（mtDNA）序列。该缨翅目昆虫 mtDNA 具有后生动物 mtDNA 序列中通常发现的 13 个蛋白编码基因（PCGs）。存在一个包括 atp6、atp8、cox3、nad3 和 nad5 的大片段易位以及 12S rRNA 基因的重复。这种重排似乎不会影响核苷酸组成，尽管与其他多翅目昆虫相比，mtDNA 的某些部分的氨基酸组成存在偏向性。基于使用所有 PCGs 的核苷酸序列与两个 rRNA 基因以及所有 PCGs 的氨基酸序列串联的系统发育分析，A. japonica 与典型的竹节虫亚目（Verophasmatodea）为姐妹群。
