武铠蛱蝶线粒体基因组全序列测定和分析

Sequencing and analysis of the complete mitochondrial genome of Chitoria ulupi( Lepidoptera: Nymphalidae)

【目的】了解闪蛱蝶亚科属间及种间的分子系统进化关系。【方法】采用PCR步移法对武铠蛱蝶Chitoria ulupi线粒体基因组全序列进行了测定和分析。基于线粒体基因组13个蛋白质编码基因的核苷酸序列构建了38种鳞翅目昆虫的系统发育树。【结果】分析结果表明,武铠蛱蝶线粒体基因组全长15 279 bp,包括13个蛋白质编码基因、22个tRNA基因、2个rRNA基因和一段长度为391 bp的A+T富含区,基因排列顺序与其他已知近缘种昆虫相同。武铠蛱蝶线粒体基因组中存在很高的A+T含量(79.9%)。13个蛋白质编码基因中,COII以TTG作为起始密码子,COI以CGA作为起始密码子外,其余均为昆虫典型的起始密码子ATN。COII和ND4基因使用了不完全终止密码子T,其余基因均以典型的TAA为终止密码子。在所测得的22个tRNA基因中,除tRNASer(AGN)缺少DHU臂外,其余tRNA均能形成典型的三叶草结构。与其他多数鳞翅目昆虫一样,武铠蛱蝶的A+T富含区中有一段由ATAGAA引导的保守的多聚T结构,长度为21 bp,并散布着一些长短不一的串联重复单元。系统发育树结果显示,总科级别的系统发育关系为:卷蛾总科+(凤蝶总科+(螟蛾总科+(夜蛾总科+蚕蛾总科+尺蛾总科)));在蛱蝶科物种中,武铠蛱蝶与猫蛱蝶Timelaea maculate亲缘关系最近。【结论】基于分子标记构建的鳞翅目昆虫系统发育关系与传统的形态学分类结果基本一致。

【Aim】To explore the intergeneric and interspecific molecular and evolutionary relationships of Apaturinae. 【Methods 】The complete mitochondrial genome of Chitoria ulupi was determined and analyzed by using polymerase chain reaction amplification and prime walking. Based on nucleotide sequences of 13 protein coding genes（ PCGs）,the phylogenetic tree of 38 lepidopteran species was constructed using maximum parsimony（ MP） method. 【Results】The results indicated that the complete mitochondrial genome of C. ulupi is a circular molecule of 15 279 nucleotides,including 13 protein coding genes,22 tRNA genes,2 rRNA genes and a 391 bp A ＋ T-rich region. The arrangement of genes in C. ulupi is consistent with the sequence of other closely related species. The mitochondrial genome of C. ulupi is biased toward a high A ＋ T content（ 79. 9%）. All protein coding genes start with a typical ATN initiation codon,except that the COI starts with the CGA codon and the COII begins with the TTG codon. Majority of the 13 PCGs in C. ulupi have a complete termination codon（ TAA or TAG）,except for the COII and ND4 genes which have incomplete stop codons（ T）. All tRNAs show the classic clover-leaf structure,except that the dihydrouridine（ DHU） arm of tRNASer（ AGN）forms a simple loop. The C. ulupi A ＋ T-rich region contains some conserved structures including a structure combing the motif ATAGAA,21 bp poly（ T） stretch and a microsatellite（ AT）nelement,which is similar to thosefound in the mitogenomes of other related species. The results of phylogenetic tree showed that the phylogenetic relationship at the superfamily level is Tortricoidea ＋（ Papilionoidea ＋（ Pyraloidea ＋（ Noctuoidea ＋ Bombycoidea ＋ Geometroidea）））,and within the Nymphalidae group,C. ulupi is closely related with Timelaea maculate. 【Conclusion 】 The phylogenetic relationship of lepidopteran species based on molecular markers is basically consistent with the results of the traditional morphological classification.