title: Identification of three cytochrome P450 genes in the Chagas' disease vector Triatoma infestans: Expression analysis in deltamethrin susceptible and resistant populations.
abstract: Cytochrome P450 monooxygenases play a predominant role in the metabolism of insecticides. Many insect P450 genes have frequently been associated with detoxification processes allowing the insect to become tolerant or resistant to insecticides. The increases of expression of P450 genes at transcriptional level are often consider responsible for increasing the metabolism of insecticides and seems to be a common phenomenon in the evolution of resistance development in insects. As pyrethroid resistance has been detected in Triatoma infestans, it was of interest to analyze genes associated with resistance to insecticides such as those encoding for cytochromes P450. With this purpose, the cDNA sequences of three cytochrome P450 genes (CYP4EM7, CYP3085B1, and CYP3092A6) were identified in this species. Primers and specific Taqman probes were designed from these sequences to determine their expression by quantitative PCR. The mRNA levels of the cytochrome P450 genes identified were determined from total RNA extracted from pools of fat body collected from individuals of different resistant and susceptible strains of T. infestans, and at different interval times after the topical application of the lethal doses 50% (LD50) of deltamethrin on the ventral abdomen of insects belonging to the different populations analyzed. It was detected overexpression of the CYP4EM7 gene in the most resistant strain of T. infestans and the expression of the three cytochrome P450 genes isolated was induced by deltamethrin in the susceptible and resistant populations included in this study. These results suggest that these genes would be involved in the detoxification of deltamethrin and support the hypothesis that considers to the cytochrome P450 genes of importance in the development of pyrethroid resistance.
authors.affiliation: Instituto de Investigaciones en Ciencias de la Salud (INICSA), CONICET and Cátedra de Bioquímica y Biología Molecular, Facultad de Ciencias Médicas, Universidad Nacional de Córdoba, Córdoba, Argentina.
authors.forename: Carla G
authors.initials: CG
authors.lastname: Grosso
authors.affiliation: Instituto de Investigaciones en Ciencias de la Salud (INICSA), CONICET and Cátedra de Bioquímica y Biología Molecular, Facultad de Ciencias Médicas, Universidad Nacional de Córdoba, Córdoba, Argentina.
authors.forename: María J
authors.initials: MJ
authors.lastname: Blariza
authors.affiliation: Centro de Referencia de Vectores (CeReVe), Ministerio de Salud de la Nación, Córdoba, Argentina.
authors.forename: Gastón
authors.initials: G
authors.lastname: Mougabure-Cueto
authors.affiliation: Centro de Investigaciones de Plagas e Insecticidas (CIPEIN, CITEFA-CONICET), Buenos Aires, Argentina.
authors.forename: María I
authors.initials: MI
authors.lastname: Picollo
authors.affiliation: Instituto de Investigaciones en Ciencias de la Salud (INICSA), CONICET and Cátedra de Bioquímica y Biología Molecular, Facultad de Ciencias Médicas, Universidad Nacional de Córdoba, Córdoba, Argentina. Electronic address: bgarcia@biomed.uncor.edu.
authors.forename: Beatriz A
authors.initials: BA
authors.lastname: García
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D014355:Chagas Disease / Q000635:transmission; D003577:Cytochrome P-450 Enzyme System / Q000235:genetics*; D005260:Female; D015870:Gene Expression; D006801:Humans; D007303:Insect Vectors / Q000187:drug effects / Q000235:genetics* / Q000382:microbiology; D007305:Insecticide Resistance; D008297:Male; D009570:Nitriles / Q000494:pharmacology; D021261:Parasitic Sensitivity Tests; D010802:Phylogeny; D011722:Pyrethrins / Q000494:pharmacology; D017422:Sequence Analysis, DNA; D014224:Triatoma / Q000187:drug effects / Q000235:genetics* / Q000382:microbiology
chemical_list: D009570:Nitriles; D011722:Pyrethrins; C017180:decamethrin; D003577:Cytochrome P-450 Enzyme System
keywords: Chagas' disease vector; P450 genes; Triatoma infestans