Impact of glyphosate and benzo[a]pyrene on the tolerance of mosquito larvae to chemical insecticides. Role of detoxification genes in response to xenobiotics

• Published in: Aquatic toxicology Vol. 93; no. 1; pp. 61 - 69
• Main Authors: Riaz, Muhammad Asam, Poupardin, Rodolphe, Reynaud, Stéphane, Strode, Clare, Ranson, Hilary, David, Jean-Philippe
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 04.06.2009; Amsterdam; New York: Elsevier Science; Elsevier
• Subjects: Aedes - enzymology; Aedes - genetics; Aedes - metabolism; Aedes aegypti; Animal, plant and microbial ecology; Animals; Applied ecology; Benzo(a)pyrene - pharmacokinetics; Benzo(a)pyrene - toxicity; benzopyrene; Biological and medical sciences; Biological Assay; Cytochrome P-450 Enzyme System - genetics; Cytochrome P-450 Enzyme System - metabolism; Cytochrome P450 monooxygenases; Detoxification; Drug Interactions; Ecotoxicology, biological effects of pollution; environmental exposure; enzyme activity; Esterases; Esterases - genetics; Esterases - metabolism; Fundamental and applied biological sciences. Psychology; Gene Expression Regulation, Enzymologic - drug effects; gene induction; General aspects; genes; Glutathione S-transferases; Glutathione Transferase - genetics; Glutathione Transferase - metabolism; Glycine - analogs & derivatives; Glycine - pharmacokinetics; Glycine - toxicity; Glyphosate; imidacloprid; Imidazoles - pharmacokinetics; Imidazoles - toxicity; Inactivation, Metabolic - genetics; Induction; insecticide resistance; Insecticides; Insecticides - pharmacokinetics; Insecticides - toxicity; Larva - enzymology; Larva - genetics; Larva - metabolism; larvae; metabolic detoxification; Mosquitoes; Neonicotinoids; Nitro Compounds - pharmacokinetics; Nitro Compounds - toxicity; Oligonucleotide Array Sequence Analysis; Oxidative stress; permethrin; Permethrin - pharmacokinetics; Permethrin - toxicity; propoxur; Propoxur - pharmacokinetics; Propoxur - toxicity; Resistance; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger - biosynthesis; RNA, Messenger - genetics; sublethal effects; Techniques; transcription (genetics); Xenobiotics; Resistance; Oxidative stress; Mosquitoes; Induction; Detoxification; Insecticides; Aedes aegypti; Glutathione S-transferases; Esterases; Cytochrome P450 monooxygenases; Xenobiotics; Insecticide; Toxicity; Insecta; Biological marker; Systemic; Glyphosate; Persistent organic pollutant; Aquatic environment; Glutathione transferase; Developmental stage; Xenobiotic; Organic compounds; Hydrocarbon; Benzopyrene; Ecotoxicology; Enzyme; Transferases; Cytochrome P450; Pesticides; Parasite; Tolerance; Organic phosphonate; Polycyclic aromatic compound; Herbicide; Sensitivity resistance; Larva; Aminoacid; Arthropoda; Culicidae; Hydrolases; Ectoparasite; Invertebrata; Diptera
• ISSN: 0166-445X; 1879-1514
• DOI: 10.1016/j.aquatox.2009.03.005

The effect of exposure of Aedes aegypti larvae for 72 h to sub-lethal concentrations of the herbicide glyphosate and the polycyclic aromatic hydrocarbon benzo[a]pyrene on their subsequent tolerance to the chemical insecticides imidacloprid, permethrin and propoxur, detoxification enzyme activities and transcription of detoxification genes was investigated. Bioassays revealed a significant increase in larval tolerance to imidacloprid and permethrin following exposure to benzo[a]pyrene and glyphosate. Larval tolerance to propoxur increased moderately after exposure to benzo[a]pyrene while a minor increased tolerance was observed after exposure to glyphosate. Cytochrome P450 monooxygenases activities were strongly induced in larvae exposed to benzo[a]pyrene and moderately induced in larvae exposed to imidacloprid and glyphosate. Larval glutathione S-transferases activities were strongly induced after exposure to propoxur and moderately induced after exposure to benzo[a]pyrene and glyphosate. Larval esterase activities were considerably induced after exposure to propoxur but only slightly induced by other xenobiotics. Microarray screening of 290 detoxification genes following exposure to each xenobiotic with the DNA microarray Aedes Detox Chip identified multiple detoxification and red/ox genes induced by xenobiotics and insecticides. Further transcription studies using real-time quantitative RT-PCR confirmed the induction of multiple P450 genes, 1 carboxy/cholinelesterase gene and 2 red/ox genes by insecticides and xenobiotics. Overall, this study reveals the potential of benzo[a]pyrene and glyphosate to affect the tolerance of mosquito larvae to chemical insecticides, possibly through the cross-induction of particular genes encoding detoxification enzymes.