title: Diversity and frequency of kdr mutations within Anopheles sinensis populations from Guangxi, China.
abstract: Anopheles sinensis is a major vector of malaria in China and its control is under great threat as the development of insecticide resistance. Voltage-gated sodium channel (VGSC) is the target of several classes of insecticides. Genetic mutations of VGSC have been documented to confer knockdown resistance (kdr) to dichlorodiphenyltrichloroethane (DDT) and pyrethroids in mosquitoes. To control this vector efficiently, it is important to know the resistance-associated genetic mutations, their distribution frequencies and genealogical relations.
  
  
  
  Three hundreds and thirteen (313) adults of An. sinensis collected from nine locations across Guangxi Zhuang Autonomous Region were used. The partial sequence of the An. sinensis voltage gated sodium channel gene (AS-VGSC) containing codon 1014 was sequenced. PHASE2.1 was used to construct the haplotypes of each individual, and the accuracy of haplotypes was further confirmed by clone sequencing. The genealogical relations of kdr mutations in AS-VGSC was analysed using TCS 2.1 and Network 5.0.
  
  
  
  Sixteen AS-VGSC haplotypes including seven haplotypes carrying non-synonymous mutations at codon 1014, and fifty-five AS-VGSC genotypes were identified from 313 mosquitoes collected from nine geographical locations across Guangxi. The number of haplotypes in each of the nine populations ranged from 5 to 13. The frequency of haplotypes carrying kdr mutations ranged from 2.7 to 80.0 % within the nine populations, of which 1014C was unexpectedly high in the northeast of Guangxi. Genealogical analysis suggested multiple origins of kdr mutations in An. sinensis.
  
  
  
  Diverse haplotypes of AS-VGSC are distributed in Guangxi. The presence of haplotypes carrying mutations at codon 1014 indicates a risk of pyrethroid and DDT resistance. The kdr mutations show differential distribution geographically, with high frequencies occurred in the northeast of Guangxi. Genealogical analysis suggests multiple origins of kdr mutations in An. sinensis populations in Guangxi. These findings have important practical implications for the sustainability of An. sinensis control programmes.
authors.affiliation: State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China.|University of Chinese Academy of Sciences, Beijing, 100049, China.
authors.forename: Chan
authors.initials: C
authors.lastname: Yang
authors.affiliation: Guangxi Zhuang Autonomous Region Centre for Diseases Control and Prevention, Nanning, 530028, China.
authors.forename: Xiangyang
authors.initials: X
authors.lastname: Feng
authors.affiliation: State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China.
authors.forename: Zushi
authors.initials: Z
authors.lastname: Huang
authors.affiliation: State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China.
authors.forename: Mei
authors.initials: M
authors.lastname: Li
authors.affiliation: State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China. qiuxh@ioz.ac.cn.|University of Chinese Academy of Sciences, Beijing, 100049, China. qiuxh@ioz.ac.cn.
authors.forename: Xinghui
authors.initials: X
authors.lastname: Qiu
mesh_terms: D000818:Animals; D000852:Anopheles / Q000187:drug effects* / Q000201:enzymology* / Q000235:genetics; D002681:China; D014644:Genetic Variation; D006239:Haplotypes; D007305:Insecticide Resistance; D009154:Mutation; D015995:Prevalence; D017422:Sequence Analysis, DNA; D061566:Voltage-Gated Sodium Channels / Q000235:genetics*
chemical_list: D061566:Voltage-Gated Sodium Channels
keywords: Anopheles sinensis; Genealogical analysis; Guangxi Zhuang Autonomous Region; Haplotype; Knockdown resistance (kdr); Voltage-gated sodium channel (VGSC)