茶六斑褐锦斑蛾Sorita pulchella线粒体基因组特征与系统发育分析

Characterization of the mitochondrial genome and phylogenetic analysis of Sorita pulchella

【目的】了解茶六斑褐锦斑蛾(Sorita pulchella)线粒体基因组特征,探究其分类地位,并分析蛾类高级分类阶元的系统发育关系。【方法】野外采集西藏自治区林芝市易贡茶场发生的茶六斑褐锦斑蛾。采用高通量测序的方法获得线粒体基因组序列并分析其基因组结构特征;用最大似然法和贝叶斯法构建系统发育树,探讨鳞翅目斑蛾科昆虫系统发育关系。【结果】茶六斑褐锦斑蛾(GenBank登录号:MZ157403)线粒体基因组序列的总长度为15216 bp,编码37个基因,即13个蛋白质编码的基因、22个tRNA基因、2个rRNA基因(rrnL和rrnS)和1个A+T富含区。其基因组成与其它已知的鳞翅目昆虫一致。蛋白质编码基因的A+T的含量为77.7%,长度为10830 bp。tRNA中的A+T的含量则为80.9%。22个tRNA的二级结构仅trnS1缺少二氢尿嘧啶环,其它tRNA的二级结构都为典型的三叶草型。20个种进行了系统发育分析,包括两个外群。贝叶斯系统发育树显示斑蛾科内的系统发生关系为:(Zeuzera multistrigata+Endoxyla cinereus)+(((Apoda limacodes+Narosa nigrisigna)+((Iragoides fasciata+(Thosea sinensis+Thosea sythoffi))+(Parasa consocia+(Mahanta tanyae+Monema flavescens))))+((Phauda flammans+Zygaena filipendulae+((Illiberis pruni+Illiberis ulmivora)+(Pidorus atratus+((Amesia sanguiflua+Rhodopsona rubiginosa)+Eterusia aedea+(Histia rhodope+Sorita pulchella)))))))。最大似然树的结果为:(Endoxyla cinereus+Zeuzera multistrigata+((Apoda limacodes+Narosa nigrisigna)+((Iragoides fasciata+(Thosea sinensis+Thosea sythoffi))+(Parasa consocia+(Mahanta tanyae+Monema flavescens)))+(Zygaena filipendulae+(Phauda flammans+((Illiberis pruni+Illiberis ulmivora)+(Pidorus atratus+((Amesia sanguiflua+Rhodopsona rubiginosa)+(Histia rhodope+(Eterusia aedea+Sorita pulchella)))))))))。【结论】斑蛾科和刺蛾科皆为单系群。贝叶斯系统发育结果表示,六星斑蛾和朱红毛斑蛾分化较早,梨星毛虫与榆斑蛾互为姐妹群,玉带斑蛾单独成为一支,釉锦斑蛾和黑心赤眉锦斑蛾互为姐妹群,茶六斑褐锦斑蛾与重阳木褐锦斑蛾互为姐妹群,它们组成的一支再与茶柄脉锦斑蛾互为姐妹群。

【Objective】The objective of this study was to investigate the characteristics of mitochondrial genome of Sorita pulchella,to explore its taxonomic status,and to analyze the phylogenetic relationship of higher taxonomic category of moths.【Method】The samples of S.pulchella was gathered in the Yigong Tea Farm in Nyingchi City,Tibet Autonomous Region.High-throughput sequencing was used to obtain the mitochondrial genome sequence of S.pulchella,and its genome characteristics were analyzed.Maximum Likelihood and Bayesian inference methods were used to establish phylogenetic tree to explore the phylogenetic relationships among moths.【Result】The results showed that the whole length of the mitochondrial genome sequence of S.pulchella(GenBank accession:MZ157403)is 15216 bp,which encodes 37 genes:13 protein-coding genes,22 tRNA genes,2 rRNA genes(rrnL and rrnS)and an A+T-rich region.The gene content is consistent with the mitochondrial genome structure of other published Lepidoptera insects.The A+T content of protein-coding genes,whose length is 10830 bp,is 77.7%.The A+T content of tRNA is 80.9%.The secondary structure of 22 tRNAs is typical of the clover type except trnS1,whose dihydrouracil ring and arm is missing.Phylogenetic analysis of 20 species including two outgroup taxa,was conducted.Bayesian phylogenetic tree shows that the phylogenetic relationships of ygaenidae is:(Zeuzera multistrigata+Endoxyla cinereus)+(((Apoda limacodes+Narosa nigrisigna)+((Iragoides fasciata+(Thosea sinensis+Thosea sythoffi))+(Parasa consocia+(Mahanta tanyae+Monema flavescens))))+((Phauda flammans+Zygaena filipendulae+((Illiberis pruni+Illiberis ulmivora)+(Pidorus atratus+((Amesia sanguiflua+Rhodopsona rubiginosa)+Eterusia aedea+(Histia rhodope+Sorita pulchella))))))).The result of Maximum likelihood of phylogenetic tree is:(Endoxyla cinereus+Zeuzera multistrigata+((Apoda limacodes+Narosa nigrisigna)+((Iragoides fasciata+(Thosea sinensis+Thosea sythoffi))+(Parasa consocia+(Mahanta tanyae+Monema flavescens)))+(Zygaena filipendulae+(Phauda flammans+((Illiberis pruni+Illiberis ulmivora)+(Pidorus atratus+((Amesia sanguiflua+Rhodopsona rubiginosa)+(Histia rhodope+(Eterusia aedea+Sorita pulchella))))))))).【Conclusion】Zygaenidae and Limacodidae are both monophyletic.The results of phylogenetic analyses showed that Zygaena filipendulae and Phauda flammans differentiate earlier.Illiberis pruni is the sister group of Illiberis ulmivora.Pidorus atratus is monophyletic.Amesia sanguiflua is sister group to Rhodopsona rubiginosa.S.pulchella is sister group to Histia rhodope,and together they are sister group to Eterusia aedea.