赭翅臀花金龟线粒体全基因组测序及分析

Sequencing and analysis of the complete mitochondrial genome of Campsiura mirabilis(Coleoptera:Scarabaeidae)

【目的】测定和分析赭翅臀花金龟Campsiura mirabilis线粒体全基因组,并基于线粒体基因组序列探讨金龟科(Scarabaeidae)的系统发育关系。【方法】采用Illumina Hiseq X Ten测序平台,首次测定了赭翅臀花金龟的线粒体全基因组序列,并对其基因结构特点和碱基组成进行分析。结合GenBank中已公布的金龟科54个种的线粒体基因组序列,对该科共55个种线粒体蛋白质编码基因(protein-coding genes,PCGs)的选择压力进行了分析;并基于PCGs和rRNA基因序列,选取锹甲科(Lucanidae)的美国深山锹Lucanus mazama作为外群分别使用最大似然法(maximum likelihood method,ML)和贝叶斯法(Bayesian inference,BI)构建金龟科的系统发育树。【结果】赭翅臀花金龟的线粒体基因组(GenBank登录号:MT548771)全长16123 bp,包括13个PCGs、22个tRNA基因、2个rRNA基因和一个D-loop区(控制区),没有发现基因重排现象;22个tRNA基因中除trnS1缺失DHU臂,其余均可形成典型的三叶草式二级结构。赭翅臀花金龟线粒体基因组的碱基组成具有AT偏好性,全基因组的AT-skew大于0,GC-skew小于0。金龟科线粒体基因组的PCGs的K_(a)/K_(s)值都低于1,表明这13个PCGs都经历了纯化选择。基于线粒体基因组13个PCGs和2个rRNA基因序列的金龟科的系统发育关系为((蜉金龟亚科(Aphodiinae)+金龟亚科(Scarabaeinae))+(鳃金龟亚科(Melolonthinae)+(花金龟亚科(Cetoniinae)+(丽金龟亚科(Rutelinae)+犀金龟亚科(Dynastinae)))))。【结论】本研究测定和分析了赭翅臀花金龟的线粒体基因组,并分析了金龟科的系统发育关系,结果显示金龟亚科、花金龟亚科、丽金龟亚科、犀金龟亚科和鳃金龟亚科均为单系群。

【Aim】To sequence and analyze the complete mitochondrial genome(mtgemome)of Campsiura mirabilis,and to discuss the phylogenetic relationship of the family Scarabaeidae based on mtgenome sequences.【Methods】The whole mtgenome of C.mirabilis was firstly sequenced on the Illumina Hiseq X Ten platform,and the gene structure characteristics and base composition of the C.mirabilis mtgenome were analyzed.Combined with the 54 mtgemome sequences published in GenBank,the selection pressure of protein-coding genes(PCGs)in the mtgenome of 55 species in Scarabaeidae was analyzed.The phylogenetic tree of Scarabaeidae was constructed with Lucanus mazama in Lucanidae as the outgroup based on PCG and rRNA gene sequences using maximum likelihood(ML)and Bayesian inference(BI)methods.【Results】The full-length of the C.mirabilis mtgenome(GenBank accession no.:MT548771)is 16123 bp,including 13 PCGs,22 tRNA genes,2 rRNA genes and a D-loop region(control region),without gene rearrangement.All the 22 tRNA genes show the typical cloverleaf secondary structure except for the absence of DHU arm of trnS1.The base composition of the mtgenome of C.mirabilis shows a higher AT content with the positive AT-skew and negative GC-skew.The K_(a)/K_(s)values of PCGs of Scarabaeidae are all less than 1,indicating that all of these 13 PCGs have experienced purifying selection.The phylogenetic relationship in Scarabaeidae based on the sequences of the 13 PCGs and 2 rRNA genes was:((Aphodiinae+Scarabaeinae)+(Melolonthinae+(Cetoniinae+(Rutelinae+Dynastinae)))).【Conclusion】In this study we sequenced and analyzed the mtgenome of C.mirabili,and analyzed the phylogenetic relationship of Scarabaeidae.Our results indicate that the subfamilies of Scarabaeinae,Cetoniinae,Rutelinae,Dynastinae and Melolonthinae are monophyletic groups.