枣食芽象甲线粒体基因组全序列测定与系统发育分析

【目的】从线粒体基因组水平上探讨枣食芽象甲Scythropus yasumatsui与近缘种的系统发育关系。【方法】利用Illumina MiSeq测序平台对枣食芽象甲线粒体基因组进行测序，对基因组序列进行拼装、注释和特征分析；利用贝叶斯法和最大似然法构建基于象甲科13个物种的线粒体基因组13个蛋白质编码基因核苷酸序列的系统发育树。【结果】结果表明，枣食芽象甲线粒体基因组全长为16 472 bp (GenBank登录号: MF807224)，包含13个蛋白质编码基因、22个tRNA基因、2个rRNA基因和2个非编码控制区，37个基因的排列顺序与祖先昆虫的线粒体基因排列顺序一致。13个蛋白质编码基因的起始密码子为ATN，其中除了cob和nad1基因的完全终止密码子为TAG外，其余11个基因的完全终止密码子为TA(A)。22个tRNA基因中除了trnS1缺少DHU臂，反密码子由GCT变为TCT外，其余均能形成典型的三叶草结构。基于13个蛋白质编码基因序列构建的系统发育树结果显示，象甲科8个亚科系统发育关系为：(((隐喙象亚科(Cryptorhynchinae)+(象虫亚科(Curculioninae)+魔喙象亚科(Molytinae)))+长小蠹亚科(Platypodinae))+(粗喙象亚科(Entiminae)+Cyclominae亚科))+隐颏象亚科(Dryophthorinae)+小蠹亚科(Scolytinae))。【结论】在13种象甲科昆虫物种中，同属于粗喙象亚科的枣食芽象甲与南美果树象甲Naupactus xanthographus在系统发育树中聚为同一分支，表明基于线粒体基因组全序列的分子系统发育结果与传统的形态分类结果是一致的。

Sequencing and phylogenetic analysis of the complete mitochondrial genome ofScythropusyasumatsui(Coleoptera: Curculionidae)

【Aim】 To explore the phylogenetic relationship between Scythropus yasumatsuiand related species at the mitochondrial genome level. 【Methods】 Using Illumina MiSeqplatform, the mitochondrial genome of S. yasumatsui was sequenced, and the genome sequenceswere assembled, annotated and characterized. Based on the nucleotide sequences of 13protein-coding genes in the mitochondrial genome, the Bayesian and ML phylogenetic treesof 13 species of the family Curculionidae were constructed. 【Results】 The results showedthat the sequence length of the mitochondrial genome of S. yasumatsui is 16 472 bp (GenBankaccession no.: MF807224), including 13 protein-coding genes (PCGs), 22 tRNA genes, 2 rRNAgenes and 2 non-coding regions, and the order of genes is consistent with that of theancestral insect mitochondrial genes. All of the 13 PCGs use ATN as the start codon, andexcept that cob and nad1 use TAG as the termination codon, other 11 PCGs use TA(A) as thetermination codon. All of the 22 tRNA genes were predicted to contain typical cloverleafsecondary structures except the gene trnS1 lacking DHU arm and changing anticodon from GCTto TCT. Phylogenetic tree based on the nucleotide sequences of 13 PCGs showed that thephylogenetic relationship among eight subfamilies of the family Curculionidae was:(((Cryptorhynchinae+(Curculioninae+Molytinae))+Platypodinae)+(Entiminae+Cyclominae))+Dryophthorinae+Scolytinae). 【Conclusion】 The phylogenetic tree based on themitochondrial genome showed that among the 13 species of the family Curculionidae, S.yasumatsui and Naupactus xanthographus belonging to the subfamily Entiminae clusteredtogether in the same branch of phylogenetic tree, and this result is consistent with thatof traditional morphological classification.