title: The mitochondrial genomes of Culex tritaeniorhynchus and Culex pipiens pallens (Diptera: Culicidae) and comparison analysis with two other Culex species.
abstract: Culex tritaeniorhynchus and Culex pipiens pallens are the major vectors of the Japanese encephalitis virus and Wuchereria bancrofti, the causative agent of filariasis. The knowledge of mitochondrial genomes has been widely useful for the studies on molecular evolution, phylogenetics and population genetics.
  
  
  
  In this study, we sequenced and annotated the mitochondrial (mt) genomes of Cx. tritaeniorhynchus and Cx. p. pallens, and performed a comparative analysis including four known mt genomes of species of the subgenus Culex (Culex). The phylogenetic relationships of Cx. tritaeniorhynchus, Cx. p. pallens and four known Culex mt genome sequences were reconstructed by maximum likelihood based on concatenated protein-coding gene sequences.
  
  
  
  Culex tritaeniorhynchus and Cx. p. pallens mt genomes are 14,844 bp and 15,617 bp long, both consists of 13 PCGs, 22 tRNAs, 2 rRNAs and 1 CR (not sequenced for Cx. tritaeniorhynchus). The initiation and termination codons of PCGs are ATN and TAA, respectively, except for COI starting with TCG, and COI and COII terminated with T. tRNAs have the typical clover-leaf secondary structures except for trnS ((AGN)) that is lacking the DHU stem. 16S rRNA and 12S rRNA secondary structures were drawn for the first time for mosquito mt genomes. The control region of Cx. p. pallens mt genome is 747 bp long and with four tandem repeat structures. Phylogenetic analyses demonstrated that the mt genome of Cx. tritaeniorhynchus was significantly separated from the remaining five mt genomes of Culex spp. Culex p. pipiens, Cx. p. pallens and Cx. p. quinquefasciatus formed a monophyletic clade with Cx. p. quinquefasciatus linked in the middle of the clade, and Cx. p. pallens should have the same taxonomic level as Culex p. pipiens and Cx. p. quinquefasciatus.
  
  
  
  The mt genomes of Cx. tritaeniorhynchus and Cx. p. pallens share the same gene composition and order with those of two other Culex species. Culex p. pallens of the Pipiens complex should have the same taxonomic level as Culex p. pipiens and Cx. p. quinquefasciatus investigated. We enriched the Culex mt genome data and provided a reference basis for further Culex mt genome sequencing and analyses.
authors.affiliation: Institute of Entomology and Molecular Biology, College of Life Sciences, Chongqing Normal University, Chongqing, 401331, People's Republic of China.
authors.forename: Qian-Chun
authors.initials: QC
authors.lastname: Luo
authors.affiliation: Institute of Entomology and Molecular Biology, College of Life Sciences, Chongqing Normal University, Chongqing, 401331, People's Republic of China.
authors.forename: You-Jin
authors.initials: YJ
authors.lastname: Hao
authors.affiliation: National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing, 102206, People's Republic of China.
authors.forename: Fengxia
authors.initials: F
authors.lastname: Meng
authors.affiliation: Institute of Entomology and Molecular Biology, College of Life Sciences, Chongqing Normal University, Chongqing, 401331, People's Republic of China.
authors.forename: Ting-Jing
authors.initials: TJ
authors.lastname: Li
authors.affiliation: Institute of Entomology and Molecular Biology, College of Life Sciences, Chongqing Normal University, Chongqing, 401331, People's Republic of China.
authors.forename: Yi-Ran
authors.initials: YR
authors.lastname: Ding
authors.affiliation: Institute of Entomology and Molecular Biology, College of Life Sciences, Chongqing Normal University, Chongqing, 401331, People's Republic of China.
authors.forename: Ya-Qiong
authors.initials: YQ
authors.lastname: Hua
authors.affiliation: Institute of Entomology and Molecular Biology, College of Life Sciences, Chongqing Normal University, Chongqing, 401331, People's Republic of China. bin.chen@cqnu.edu.cn.
authors.forename: Bin
authors.initials: B
authors.lastname: Chen
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D003465:Culex / Q000737:chemistry / Q000145:classification / Q000235:genetics*; D049750:Genome, Insect; D054629:Genome, Mitochondrial; D019476:Insect Proteins / Q000737:chemistry / Q000235:genetics; D007303:Insect Vectors / Q000737:chemistry / Q000145:classification / Q000235:genetics; D008969:Molecular Sequence Data; D010802:Phylogeny; D016415:Sequence Alignment
chemical_list: D019476:Insect Proteins
keywords: Characteristics; Culex; Culex pipiens pallens; Culex tritaeniorhynchus; Mitochondrial genome; Phylogenetics