A potential role for 4g family cytochrome P450s in conferring insecticide resistance in mosquitoes by altering cuticle structure

BALABANIDOU V; RIGA M ; JUÁREZ M PATRICIA; RANSON H; VONTAS J

Congreso; 61ST ESA ANNUAL MEETING; 2013

Entomological Soc America

A potential role for 4g family cytochrome P450s in conferring insecticide resistance in mosquitoes by altering cuticle structure Vasileia Balabanidou1, Maria Riga1, Patricia Juarez2, George Chalepakis1, Mark Paine3, Hilary Ranson3, Gareth Lycett3, and John Vontas1 1Department of Biology, University of Crete, Heraklion, Greece 2 Instituto de Investigaciones Bioquımicas de La Plata, Universidad Nacional de La Plata, La Plata, Argentina 3 Department of Vector Biology, Liverpool School Tropical Medicine, Liverpool UK Abstract The Anopheles gambiae cytochrome P450sCYP4G16 and CYP4G17 are the closest ortholog and paralog respectively,of the Drosophila melanogaster CYP4G1, the specific insect P450 with decarbonylase function that is involved in hydrocarbon biosynthesis.The expression of both proteins is significantly higher in the oenocytes of insecticide resistance mosquitoes, compared to susceptible. Immunohistochemical stainings and western analysis showed that the CYP4G16 (including its different isoforms) and CYP4G17 proteins are found in the head and the carcass of the abdomen and are highly expressed in oenocytes, but not the midgut or malpighiam tubules, where P450 detoxification genes have beenlocalized previously. Both proteins have been functionally co-expressed with their putative electron donor, cytochrome P450 reductase,in E coli using a fusion recombinant system, in order to determine precise catalytic activities (decarbonylase function; substrate specificity). Hydrocarbon composition isbeing analysed in insecticide resistant and susceptible mosquito strains, and following CYP4G17 and CYP4G16 depletion (RNAi), using GCMS ? based approaches. This data points to a potential role of cyp4 P450?s in insecticide resistance, via enhanced cuticular hydrocarbon biosynthesis.