黄杨绢野螟和四目扇野螟全线粒体基因组的测定与分析

Sequencing and analysis of the complete mitochondrial genome of Diaphania perspectalis and Pleuroptya inferior(Insecta:Lepidoptera)

通过PCR结合引物步移法测定了黄杨绢野螟Diaphaniaperspectalis(Walker,1859)和四目扇野螟Pleuroptya inferior(Hampson,1898)的全线粒体基因组序列,并对二者进行了初步分析。结果显示:黄杨绢野螟和四目扇野螟线粒体基因组全长分别是15 249bp和15 348bp,基因的组成和排列与其他已公布的螟蛾总科昆虫相同,均由13个蛋白质编码基因(PCGs)、22个转运RNA基因(tRNA)、2个核糖体RNA基因(rRNA)和1个长度可变的A+T富集区组成。13个蛋白质编码基因除COⅠ以CGA作为起始密码子外,其余均以ATN作为起始密码子。对于终止密码子的使用,除COⅠ、COⅡ、ND5存在不完全终止密码子T或TA外,其他均为完全终止密码子TAA。21个tRNA基因均可形成典型的三叶草二级结构,只有tRNASer(AGN)比较特殊,其二级结构缺失DHU臂,在该位置形成了一个环。黄杨绢野螟和四目扇野螟线粒体基因组的A+T富集区位于12S rRNA和tRNAMet之间,长度分别为344bp和366bp,A+T含量明显高于线粒体基因组中37个编码基因。此外,A+T富集区还存在一些保守序列、poly-T和poly-A结构以及串联重复序列。基于13个蛋白质编码基因采用最大似然法(ML)和贝叶斯法(BI)对螟蛾总科10个亚科进行初步的系统进化分析,两种结果均符合以往形态学和分子数据的研究结果。

Complete mitochondrial genomes（mitogenomes）of Diaphaniapers pectalis（Walker,1859）and Pleuroptya inferior（Hampson,1898）were sequenced and primarily analyzed by PCR with primer walking.The results showed that the mitogenomes sequence of D.perspectalis and P.inferior were15 249 bp and 15 348 bp in length.The composition and arrangement of two species mitogenomes were consistent with other sequenced Pyraloidea,and included 13 protein-coding genes（PCGs）,22 transfer RNA（tRNA）,two ribosomal RNA（rRNA）,and a variable A＋T-rich region.All protein-coding genes began with the typical ATN codon except for COⅠwhich began with CGA.For stop codon,TAA was used in all the PCGs,while the COⅠ,COⅡand ND5 existed incomplete stop codon T or TA.All tRNAs had the typical cloverleaf secondary structure except for tRNASer（AGN）which lacks the DHU stem.The A＋T-rich region of D.perspectalis and P.inferior was located between the 12 S rRNAand tRNA^Met,and their lengths were 344 bp and 366 bp,displaying the higher A＋T content than 37 genesin the mitogenome.In addition,there are some conserved sequences,poly-T and poly-A structures,as well as different tandem repeats in the A＋T-rich regions.Maximum likelihood（ML）and Bayesian inference（BI）phylogenetic analyses were performed based on the 13 PCGs in TenPyraloidea subfamilies show that the results of this study accord with previous morphological and molecular taxonomies of this group.