沟眶象线粒体基因组及象甲科系统发育分析

Analysis of the Mitochondrial Genome of Eucryptorrhynchus Scrobiculatus(Coleoptera:Curculionidae)and a Phylogenetic Analysis of Curculionidae

利用二代测序方法获得了沟眶象线粒体基因组序列,并基于象甲科29个物种(内群)和叶甲科3个物种(外群)的37个线粒体基因核苷酸序列和13个蛋白质编码基因氨基酸序列,通过最大似然法和贝叶斯法构建了象甲科的系统发育树。结果表明:沟眶象的13个蛋白质编码基因只有nad1利用TTG作为起始密码子,其余蛋白质编码基因的起始密码子都以ATN起始;终止密码子除cox1和nad4以不完整的T结尾外,其余蛋白质编码基因都是以TAA和TAG作为终止密码子;除trnS1因缺少DHU臂而形成一个简单的环,无法形成完整的三叶草形状,剩下的tRNA基因均能形成完整的三叶草形状;trnS1的反密码子不是常见的GCU而是UCU。2种系统发育分析产生相同的拓扑结构:隐喙象亚科、龟象亚科、魔喙象亚科、小蠹亚科、粗喙象亚科和隐颏象亚科为单系群,而象虫亚科为非单系群;沟眶象与Trigonopterus carinirostris+(T.jasminae+T.kotamobagensis)为姐妹群。本研究获得了沟眶象的线粒体基因组序列,重建了象甲科的系统发育关系,明确了沟眶象的系统发育位置,有利于更加全面地理解象甲科系统发育关系和线粒体基因组学。

The nearly complete mitochondrial genome of Eucryptorrhynchus scrobiculatus was sequenced by next-generation sequencing(NGS)method,and constructed the phylogenetic trees using Maximum Likelihood and Bayesian inference methods,based on the nucleotide sequences from mitochondrial genome of 37 genes and the amino acid sequences from thirteen protein-coding genes of 29 Curculionidae species(ingroup)and 3 Chryso-melidae species(outgroup).The findings revealed that most of protein-coding genes start with the codons of ATN except for the nad1 genes.The latter one protein-coding genes use TTG as start codons.While cox1 and nad4 em-ploy the incomplete T as the stop codon,the remaining nine protein-coding genes terminate with TAA or TAG.All tRNA genes can be folded into typical cloverleaf structure,with the except of the trnS1-AGN.Both phylogen-etic inference methods produced a similar tree topological structure:the subfamilie Cryptorhynchinae,Ceuto-rhynchina,Molytinae,Scolytinae,Entiminae and Dryophthorinae were monophyletic.However the subfamilies Curculioninae were non-monophyletic.The E.scrobiculatus is sister to Trigonopterus carinirostris+(T.jas-minae+T.kotamobagensis).In this paper,we obtained the complete mitochondrial genome sequence of the E.scrobiculatus,reconstructed the phylogeny of the Curculionidae family,and clarified the phylogenetic position of the E.scrobiculatus,which is beneficial to a more comprehensive understanding of the phylogeny and mitochon-drial genomics of the Curculionidae family.