Chen L.,Nanjing Medical University |
Chen L.,Key Laboratory of Modern Pathogen Biology of Jiangsu Province |
Zhong D.,University of California at Irvine |
Zhang D.,Nanjing Medical University |
And 24 more authors.
PLoS ONE | Year: 2010
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. © 2010 Chen et al.
Zhang J.,Nanjing Medical University |
Zhang J.,Key Laboratory of Modern Pathogen Biology of Jiangsu Province |
Yang M.,Nanjing Medical University |
Yang M.,Key Laboratory of Modern Pathogen Biology of Jiangsu Province |
And 14 more authors.
Parasitology Research | Year: 2011
The prag01 gene (GenBank accession no. EU073017) was cloned from Culex pipiens pallens. An open reading frame of 270 bp was found to encode a putative 89-amino-acid protein which has the highest homology with Culex quinquefasciatus and Anopheles funestus. Real-time quantitative PCR analysis demonstrated that the transcription level of prag01 gene in deltamethrin-resistant strain was 1.65-fold higher than in deltamethrin-susceptible strain of C. pipiens pallens. Overexpression of prag01 gene in the mosquito C6/36 cells showed better prolification than the cells with empty vector when treated by deltamethrin. Our data for the first time approved that prag01 gene might play some role in the development of deltamethrin resistance in C. pipiens pallens. © 2011 Springer-Verlag.
Sun H.,Nanjing Medical University |
Sun H.,Key Laboratory of Modern Pathogen Biology of Jiangsu Province |
Sun L.,Nanjing Medical University |
Sun L.,Key Laboratory of Modern Pathogen Biology of Jiangsu Province |
And 16 more authors.
Parasitology Research | Year: 2011
The 40S ribosomal protein S29 (RPS29) was shown differentially expressed in deltamethrin (DM)-susceptible and resistant Culex pipiens pallens previously. Here, we cloned RPS29 from this mosquito. An open reading frame (ORF) of 171 bp was found to encode a putative protein with 56 amino acid residues, which shares more than 90% identities with other mosquito RPS29 genes. Moreover, quantitative real-time PCR analysis demonstrated that the transcriptional level of RPS29 was significantly up-regulated both in DM-resistant Cx. p. pallens and C6/36 cells compared with the susceptible ones. Over-expression of RPS29 showed a slight decrease of cell viability in DM-susceptible C6/36 cells under DM treatment and knockdown of RPS29 by siRNA comparably increased cell viability in DM-resistant cells. Our study provides evidence that RPS29 might be associated with fitness cost of DM resistance in mosquitoes for the first time. © 2011 Springer-Verlag.