西氏熊蜂线粒体基因组结构特征及系统发育分析

The Mitochondrial Genome Characteristics and Phylogenetic Analysis of Bombus sichelii

本研究利用二代测序技术对西氏熊蜂(Bombus sichelii)的线粒体基因组进行了测序、组装和注释,并对其线粒体基因组的组成、结构特征、基因重排及系统发育等方面进行了生物信息学分析。结果表明:西氏熊蜂线粒体基因组长度为15711 bp,包含13个蛋白编码基因、22个tRNA基因和2个rRNA基因;线粒体基因组全序列、蛋白编码基因的串联序列、tRNA串联序列、rRNA串联序列的A+T含量均大于80%,表现出明显的碱基偏倚;13个蛋白编码基因的起始密码子均为ATN,终止密码子为TAA,TAG或T--。tRNA二级结构预测发现,trnS 1与其他昆虫具有相同的特征,即缺少DHU臂和DHU环,其余21个tRNA均能形成典型的三叶草结构;系统发育进化分析结果高度支持西氏熊蜂与火红熊蜂(B.pyrosoma)隶属于黑熊蜂亚属(Melanobombus)。本研究首次获得西氏熊蜂线粒体基因组序列,初步鉴定了其线粒体基因组的特征,为进一步对熊蜂线粒体基因组学和系统发育关系的研究奠定了基础。

In this study,the mitochondrial genome of Bombus sichelii was sequenced by next-generation sequencing technology,then was assembled and annotated.And the composition,structural characteristics,gene rearrangement and phylogeny of the mitochondrial genome were analyzed by bioinformatics.The results showed that the mitochondrial genome of B.sichelii was 15711 bp in length,containing 13 protein-coding genes,22 tRNA genes and 2 rRNA genes.The A+T content of the whole mitochondrial genome sequence,the tandem sequence of protein-coding genes,the tandem sequence of tRNA,and the tandem sequence of rRNA were all greater than 80%,showing obvious base bias.The initiation codon of 13 protein-coding genes was ATN,and the stop codons was TAA,TAG,or T--.The secondary structure prediction of tRNAs showed that trnS 1 had the same characteristics as other insects.That is,it lacked DHU arm and DHU ring,and the other 21 tRNAs could form a typical clover structure.Phylogenetic findings support the affiliation of B.sichelii and B.pyrosoma to Melanobombus.In this study,the mitochondrial genome sequence of B.sichelii was obtained for the first time,and the characteristics of the mitochondrial genome of Bumblebee were preliminarily identified,which laid a foundation for further research on the relationship between mitochondrial genomics and phylogeny of bumblebees.