Study Of The Mediated-resistant Mechanism Of Cytochrome P450 In The House Fly

Cytochrome P450-dependent monooxygenases are a very important enzymaticsystem, which has been found in all living organisms systems examined. Thesemonooxygenases are able to metabolize a phenomenal number of endogenous andexogenous compounds.Musca domestica is an economically important hygienicpestaround the world. It can disseminate many kinds of person and animal's intestinaldisease.It is very significance for guarante the human health and Controls importantdiseases to Effectively eliminates house fly, In order to know more about resistantMechanism in house fly, efforts were given to study Cytochrome P450,The mainresults are as followed.Bioassayswere conducted in Pyrethroid resistant strains by topical application.The results showed that deltamethrin resistant strain (567 fold resistance) wasresistant to permethrin (335-fold), spinosads (4.05-fold) and fipronil (9-fold);Synergist folds are 30,the permethrin resistant strain (492-fold) was resistant todeltamethrin (153-fold), spinosads (4.38-fold) and fipronil (12-fold). Synergist foldsare 64. High resistance is Existence in Pyrethroid resistant strains, It have lower crossresistance to new insecticides too.Determined the content of cytochrome p450 and bs,the results showed thatcontent of cytochrome p450 and b5 is higher in resistant strains that in the susceptiblestrains. We determined the Cytochrome p450 activitys of abdomens toward differentsubstrantes(MROD,PNOD) in susceptible and resistant house fly (Musca domestica). Theresults showed that higher activity in the resistant strains that in the susceptiblestrains.We designed Eight pairs primers including Conserved heme-binding region ofP450 sequence used mRNA differential display RT-PCR to isolate two cDNAfragments belonging to cytochrome P450 from the M.domestica resistance todeltamethrin. Their expressions are higher in resistant than control spicies inM.domestica clearly. The deduced amino acids of M1 shows 59ï¼…and 58ï¼…identitieswith CYP6A24 and CYP6A1 from the M.domestica, and the deduced amino acids ofM2 shows 39ï¼…and 51ï¼…identities with CYP6A24 and CYP6A1 from theM.domestica.