Complete mitochondrial genome of Ctenophthalmus quadratus and Stenischia humilis in China provides insights into fleas phylogeny

Abstract

AbstractBackgroundFleas (Order Siphonaptera) are a common blood-feeding ectoparasites, which have important economic significance. Limited mitochondrial genome information has extremely impeded the study of flea biology, population genetics and phylogenetics. TheCtenophthalmus quadratusandStenischia humiliscomplete mt genomes are described in this study.MethodsC. quadratusandS. humiliswere collected from Jianchuan, Yunnan plague foci, China. The mt genome sequences were obtained by Illumina NovaSeq 6000 platform. The relationship betweenC. quadratusandS. humilisin fleas was inferred by phylogenetic analysis of mt genome sequence datasets.ResultsThe mt genomes ofC. quadratusandS. humiliswere 15,938 bp and 15,617 bp, respectively. The gene arrangement of mt genome was consistent with that of other fleas, which contain 37 genes, including 13 protein-coding genes, 22 tRNA genes and two rRNA genes. Phylogenetic analyses showed that theC. quadratusandS. humilisbelonged to different species in the same family, and were closely related toHystrichopsylla weida qinlingensisin the same family; and showed a sister relationship between the orders Siphonaptera and Mecoptera, supporting the monophyly of the order Siphonaptera.ConclusionsThis study is the first to decode the complete mt genomes of theC. quadratusandS. humilis. The results demonstrate that theC. quadratusandS. humilisare distinct species, and fleas are monophyletic. Analysis of mt genome provides novel molecular data for further studying the phylogeny and evolution of fleas.