title: Molecular ecology of pyrethroid knockdown resistance in Culex pipiens pallens mosquitoes.
abstract: Pyrethroid insecticides have been extensively used in China and worldwide for public health pest control. Accurate resistance monitoring is essential to guide the rational use of insecticides and resistance management. Here we examined the nucleotide diversity of the para-sodium channel gene, which confers knockdown resistance (kdr) in Culex pipiens pallens mosquitoes in China. The sequence analysis of the para-sodium channel gene identified L1014F and L1014S mutations. We developed and validated allele-specific PCR and the real-time TaqMan methods for resistance diagnosis. The real-time TaqMan method is more superior to the allele-specific PCR method as evidenced by higher amplification rate and better sensitivity and specificity. Significant positive correlation between kdr allele frequency and bioassay-based resistance phenotype demonstrates that the frequency of L1014F and L1014S mutations in the kdr gene can be used as a molecular marker for deltamethrin resistance monitoring in natural Cx. pipiens pallens populations in the East China region. The laboratory selection experiment found that L1014F mutation frequency, but not L1014S mutation, responded to deltamethrin selection, suggesting that the L1014F mutation is the key mutation conferring resistance to deltamethrin. High L1014F mutation frequency detected in six populations of Cx. pipens pallens suggests high prevalence of pyrethroid resistance in Eastern China, calling for further surveys to map the resistance in China and for investigating alternative mosquito control strategies.
authors.affiliation: Department of Pathogen Biology, Nanjing Medical University, Nanjing, Jiangsu, China.
authors.forename: Lin
authors.initials: L
authors.lastname: Chen
authors.forename: Daibin
authors.initials: D
authors.lastname: Zhong
authors.forename: Donghui
authors.initials: D
authors.lastname: Zhang
authors.forename: Linna
authors.initials: L
authors.lastname: Shi
authors.forename: Guofa
authors.initials: G
authors.lastname: Zhou
authors.forename: Maoqing
authors.initials: M
authors.lastname: Gong
authors.forename: Huayun
authors.initials: H
authors.lastname: Zhou
authors.forename: Yan
authors.initials: Y
authors.lastname: Sun
authors.forename: Lei
authors.initials: L
authors.lastname: Ma
authors.forename: Ji
authors.initials: J
authors.lastname: He
authors.forename: Shanchao
authors.initials: S
authors.lastname: Hong
authors.forename: Dan
authors.initials: D
authors.lastname: Zhou
authors.forename: Chunrong
authors.initials: C
authors.lastname: Xiong
authors.forename: Chen
authors.initials: C
authors.lastname: Chen
authors.forename: Ping
authors.initials: P
authors.lastname: Zou
authors.forename: Changliang
authors.initials: C
authors.lastname: Zhu
authors.forename: Guiyun
authors.initials: G
authors.lastname: Yan
mesh_terms: D000818:Animals; D003465:Culex / Q000187:drug effects* / Q000235:genetics; D005787:Gene Frequency; D007306:Insecticides / Q000494:pharmacology*; D009154:Mutation; D009570:Nitriles / Q000494:pharmacology*; D016133:Polymerase Chain Reaction; D011722:Pyrethrins / Q000494:pharmacology*
chemical_list: D007306:Insecticides; D009570:Nitriles; D011722:Pyrethrins; C017180:decamethrin