昆虫学报 ›› 2020, Vol. 63 ›› Issue (8): 1016-1027.doi: 10.16380/j.kcxb.2020.08.012

• 研究论文 • 上一篇    下一篇

基于线粒体基因组序列的鞘翅目肉食亚目水生类群系统发育分析

田天, 袁缓, 陈斌*   

  1. (重庆师范大学昆虫与分子生物学研究所, 媒介昆虫重庆市重点实验室, 重庆 401331)
  • 出版日期:2020-08-20 发布日期:2020-09-09

Phylogeny of hydradephagan water beetles (Coleoptera: Adephaga) inferred with mitochondrial genome sequences

TIAN Tian, YUAN Huan, CHEN Bin*   

  1.  (Chongqing Key Laboratory of Vector Insects, Institute of Entomology and Molecular Biology, Chongqing Normal University, Chongqing 401331, China)
  • Online:2020-08-20 Published:2020-09-09

摘要: 【目的】明确肉食亚目(Adephaga)水生类群线粒体基因组的基本特征,并基于线粒体基因组序列分析肉食亚目水生类群的系统发育关系。【方法】基于Illumina HiSeq X Ten测序技术测定了圆鞘隐盾豉甲Dineutus mellyi和齿缘龙虱Eretes sticticus的线粒体全基因组序列,对其进行了基因注释,并对其tRNA基因二级结构进行了预测分析。加上已公布的鞘翅目(Coleoptera)肉食亚目水生类群17个种的线粒体基因组序列,对该类群共19个种线粒体的蛋白质编码基因(protein-coding genes, PCGs)开展了比较基因组学分析,包括AT含量、密码子偏好性、选择压力等。基于13个PCGs的氨基酸序列和核苷酸序列,利用最大似然法(ML)和贝叶斯法(BI)分别构建鞘翅目肉食亚目水生类群的系统发育关系,并通过FcLM分析进一步评估伪龙虱科(Noteridae)和瀑甲科(Meruidae)的系统发育位置。【结果】圆鞘隐盾豉甲和齿缘龙虱的线粒体基因组全长分别为16 123 bp(GenBank登录号: MN781126)和16 196 bp(GenBank登录号: MN781132),都包含13个PCGs、22个tRNA基因、2个rRNA基因和1个D-loop区(控制区)。19个肉食亚目水生类群线粒体基因组PCGs的碱基组成都呈现A+T偏好性,在密码子使用上也都偏向于使用富含A+T的密码子;在进化过程中13个PCGs的进化模式相同,都受到纯化选择。基于线粒体基因组13个PCGs的氨基酸序列的肉食亚目水生类群的系统发育关系为(豉甲科Gyrinidae+(沼梭甲科Haliplidae+((壁甲科Aspidytidae+(两栖甲科Amphizoidae+龙虱科Dytiscidae))+(水甲科Hygrobiidae+(瀑甲科Meruidae+伪龙虱科Noteridae)))))。【结论】研究结果表明,豉甲科是肉食亚目水生类群的基部类群,接下来是沼梭甲科和龙虱总科;伪龙虱科和瀑甲科互为姐妹群,并一起作为龙虱总科内部的一个分支;两栖甲科与龙虱科具有更近的亲缘关系。

关键词:  鞘翅目, 肉食亚目, 水生甲虫, 龙虱总科, 圆鞘隐盾豉甲, 齿缘龙虱, 线粒体基因组, 系统发育

Abstract: 【Aim】 To clarify the general features of mitochondrial genomes of hydradephagan water beetles, and to analyze the phylogenetic relationship of hydradephagan water beetles based on the mitochondrial genome sequences. 【Methods】 Based on the Illumina HiSeq X Ten sequencing technology, we sequenced and annotated the complete mitochondrial genomes of Dineutus mellyi and Eretes sticticus, and predicted the secondary structures of tRNA genes. Combined with the published mitochondrial genomes of 17 species of hydradephagan water beetles, comparative genomics analyses including the AT content, codon usage bias, and selection pressure were performed on the mitochondrial protein-coding genes (PCGs) of the total 19 species. Based on the amino acid dataset and nucleotide dataset of 13 PCGs, the phylogenetic relationships of hydradephagan water beetles were reconstructed by using maximum likelihood (ML) and Bayesian (BI) methods, respectively, and the systematic position of Noteridae and Meruidae was further evaluated by FcLM analysis. 【Results】 The mitochondrial genomes of D. mellyi and E. sticticus are 16 123 bp (GenBank accession no.: MN781126) and 16 196 bp (GenBank accession no.: MN781132) in length, respectively. Each mitochondrial genome contains 13 PCGs, 22 tRNA genes, 2 rRNA genes and a D-loop region (control region). Within the 19 species of hydradephagan water beetles, the nucleotide composition biases show a higher A+T content, and the codon use bias analysis also found that there is a serious bias towards using AT-rich codons. The evolutionary rates of the 13 protein-coding genes showed a purifying selection. The phylogenetic relationship of hydradephagan water beetles based on the amino acid sequences of the 13 PCGs was: (Gyrinidae+(Haliplidae+((Aspidytidae+(Amphizoidae+Dytiscidae))+(Hygrobiidae+(Meruidae+Noteridae))))). 【Conclusion】 Our results indicate that Gyrinidae is the base group of hydradephagan water beetles, followed by Haliplidae and Dytiscoidea, Noteridae and Meruidae form a sister-group branch within Dytiscoidea, and a closer relationship exists between Amphizoidae and Dytiscidae.

Key words: Coleoptera, Adephaga, water beetles, Dytiscoidea; Dineutus mellyiEretes sticticus, mitochondrial genome, phylogeny