title: Sodium channel point mutations associated with pyrethroid resistance in Chinese strains of Culex pipiens quinquefasciatus (Diptera: Culicidae).
abstract: BACKGROUND
  Pesticide resistance due to sodium channel point mutations has been well documented in many mosquito species.
  
  
  METHODS
  We tested the resistance of six, wild, Chinese populations of the mosquito Culex pipiens quinquefasciatus to deltamethrin and cyhalothrin. The full length of the sodium channel gene was cloned and sequenced from a pooled sample of mosquitoes from each population.
  
  
  RESULTS
  Seven amino acid alterations were found (V250M, R436K, M943V, I973T, L1035F, L1035S and E1901D). Correlation between the frequencies of these mutations and the level of pesticide resistance (LC50) associated with them indicates that those at position L1035 (corresponding to position L1014F in the house fly, Musca domestica; GenBank Accession No.: X96668) are associated with resistance to deltamethrin and cyhalothrin. The frequency of the L1035F mutation was significantly correlated with resistance to deltamethrin (R2 = 0.536, P = 0.049) and cyhalothrin (R2 = 0.626, P = 0.030), and the combined frequency of the L1035F and L1035S mutations was significantly correlated with resistance to both deltamethrin (R2 = 0.661, P = 0.025), and cyhalothrin (R2 = 0.803, P = 0.008). None of the other mutations were correlated with either deltamethrin or cyhalothrin resistance. Interestingly, an HWE test indicated significant linkage between the M943V and I973T mutations (P < 0.01), but further research is required to determine the biological significance of this linkage.
  
  
  CONCLUSIONS
  Identifying these mutations may be of practical benefit to the development of pesticide resistance management programs.
authors.forename: Minghui
authors.initials: M
authors.lastname: Zhao
authors.forename: Yande
authors.initials: Y
authors.lastname: Dong
authors.forename: Xin
authors.initials: X
authors.lastname: Ran
authors.forename: Xiaoxia
authors.initials: X
authors.lastname: Guo
authors.forename: Dan
authors.initials: D
authors.lastname: Xing
authors.forename: Yingmei
authors.initials: Y
authors.lastname: Zhang
authors.forename: Ting
authors.initials: T
authors.lastname: Yan
authors.forename: Xiaojuan
authors.initials: X
authors.lastname: Zhu
authors.forename: Jianxin
authors.initials: J
authors.lastname: Su
authors.forename: Hengduan
authors.initials: H
authors.lastname: Zhang
authors.forename: Gang
authors.initials: G
authors.lastname: Wang
authors.forename: Wenjun
authors.initials: W
authors.lastname: Hou
authors.forename: Zhiming
authors.initials: Z
authors.lastname: Wu
authors.affiliation: Beijing Institute of Microbiology and Epidemiology, State Key Laboratory of Pathogen and Biosecurity, Beijing, China. aedes@126.com.
authors.forename: Chunxiao
authors.initials: C
authors.lastname: Li
authors.forename: Tongyan
authors.initials: T
authors.lastname: Zhao
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001681:Biological Assay; D002681:China; D003001:Cloning, Molecular; D003465:Culex / Q000235:genetics / Q000378:metabolism*; D008040:Genetic Linkage; D007305:Insecticide Resistance / Q000235:genetics*; D007306:Insecticides / Q000494:pharmacology; D008969:Molecular Sequence Data; D017354:Point Mutation; D011722:Pyrethrins / Q000494:pharmacology*; D015222:Sodium Channels / Q000235:genetics / Q000378:metabolism*
chemical_list: D007306:Insecticides; D011722:Pyrethrins; D015222:Sodium Channels