Acta Entomologica Sinica ›› 2020, Vol. 63 ›› Issue (8): 1016-1027.doi: 10.16380/j.kcxb.2020.08.012

• RESEARCH PAPERS • Previous Articles     Next Articles

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

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