Cloning And Preliminary Studies On Multidrug Resistance Gene From Culex Pipiens Pallens

The vector-borne diseases, including malaria, dengue, leishmaniasis, threaten human health and act as a major economic burden to the developing countries. Chemical control is still the major method for managing mosquito-borne diseases. Due to the wide and continuous usage of insecticides, mosquitoes developed insecticides-resistance frequently, which has become the major obstacle to control the mosquito-borne diseases. Identification and characterization of insecticide resistance related genes will provide further information for understanding the mechanism of insecticide resistance and selecting the target for insecticide resistance management.Our lab found that multidrug resistance protein (mdr) was associated with deltamethrin-resistance in Cx. pipiens pallens. In this investigation, we verified the differential expression levels of mdr between deltamethrin-susceptible and -resistant strains of Cx. pipiens pallens by realtime PCR.The complete Open reading frame (ORF) of mdr was cloned, sequenced and analyzed with bioinformatic software.Real-time quantitative PCR analysis demonstrated that the transcription level of mdr in deltamethrin-resistant strain was 42.10 folds higher than that in deltamethrin-susceptible strain of Cx. pipiens pallens (p<0.005);A complete mdr ORF was cloned and sequenced.It was found to encode a putative 1311 amino acids and shared 97%,74%,73% homology respectively with Cx.quinquefasciatus,Aedes aegypti and Anopheles gambiae; Cluster analysis by MEGA4.0 software was used to construct phylogenetic trees. The sequence of normalized distance analysis of mdr Cx.quinquefasciatus mosquitoes with the nearest (0.004), followed by Aedes aegypti (0.161) and Anopheles gambiae (0.201).These results suggest that mdr associated with the mosquito resistance and provide new evidence for clarifying the molecular mechanisms of insecticide resistance and establishing the new resistance testing methods.