Sensitivity To Insecticide, Gene Cloning And Sequencing Of AChE In Insecticide-resistant And-susceptible Strains Of Oomyzus Sokolowskii

The article preliminary studied insecticide-resistant in insecticide-resistant and-susceptible Oomyzus sokolowskii from the follow two aspects.The susceptibility to methamidophos and abamectin in insecticide-resistant and-susceptible Oomyzus sokolowskii was determined using drug membrane contact method. The results indicated that susceptibility to methamidophos or abamectin in insecticide-susceptible Oomyzus sokolowskii was significantly higher than fields’ insecticide-resistant populations. Field insecticide-resistance Oomyzus sokolowskii displayed13.8-20.4-folds resistance to methamidophos, and14.3～18.3-folds to avermectin. AChE sensitivity to methamidophos or DDV in insecticide-resistant Oomyzus sokolowskii was significantly lower than those in susceptible ones.By using homology clones strategies and the technology of RT-PCR with RACE, the full cDNA of ace gene from insecticide-resistant and-susceptible Oomyzus sokolowskii was isolated. The complete cDNA is2439bp; ace2genes was determined, we called OS-ace2R and OS-ace2SWe also finded two mutations in OS-ace2R, they located at Lys424Arg (AAG to AGG) and Phe394Leu (TTT to CTT). Though Protein homologous modeling analysis, we can infer that Phe394Leu and Lys424Arg mutations has nothing to do with insecticide-resistant. In addition, we obtained a sequence of1184bp that is a party of aceigene in insecticide-resistant and-susceptible Oomyzus sokolowskii, we called OS-acelRl and OS-ace1SI; encoding394amion acid.This sequences contain the conservative FGESAG, which is in all insects’ cholinesterase genes. By sequencing analysis, and finding two mutations in OS-ace1R1, they located at Phe207Val (TTT to GTT) and Ser130Phe (TCT to CCT), and though Protein homologous modeling analysis, Phe207Val mutation located at acyl pocket of AChE, that leading AChE sensitivity to insecticide in the fields’ population have fallen significantly. This is very important to the insecticide-resistant.