title: Carboxylesterase-mediated insecticide resistance: Quantitative increase induces broader metabolic resistance than qualitative change.
abstract: Carboxylesterases are mainly involved in the mediation of metabolic resistance of many insects to organophosphate (OP) insecticides. Carboxylesterases underwent two divergent evolutionary events: (1) quantitative mechanism characterized by the overproduction of carboxylesterase protein; and (2) qualitative mechanism caused by changes in enzymatic properties because of mutation from glycine/alanine to aspartate at the 151 site (G/A151D) or from tryptophan to leucine at the 271 site (W271L), following the numbering of Drosophila melanogaster AChE. Qualitative mechanism has been observed in few species. However, whether this carboxylesterase mutation mechanism is prevalent in insects remains unclear. In this study, wild-type, G/A151D and W271L mutant carboxylesterases from Culex pipiens and Aphis gossypii were subjected to germline transformation and then transferred to D. melanogaster. These germlines were ubiquitously expressed as induced by tub-Gal4. In carboxylesterase activity assay, the introduced mutant carboxylesterase did not enhance the overall carboxylesterase activity of flies. This result indicated that G/A151D or W271L mutation disrupted the original activities of the enzyme. Less than 1.5-fold OP resistance was only observed in flies expressing A. gossypii mutant carboxylesterases compared with those expressing A. gossypii wild-type carboxylesterase. However, transgenic flies universally showed low resistance to OP insecticides compared with non-transgenic flies. The flies expressing A. gossypii W271L mutant esterase exhibited 1.5-fold resistance to deltamethrin, a pyrethroid insecticide compared with non-transgenic flies. The present transgenic Drosophila system potentially showed that a quantitative increase in carboxylesterases induced broader resistance of insects to insecticides than a qualitative change.
authors.affiliation: State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China. Electronic address: cuif@ioz.ac.cn.
authors.forename: Feng
authors.initials: F
authors.lastname: Cui
authors.affiliation: State Key Laboratory of Brain and Cognitive Science, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China.
authors.forename: Mei-Xia
authors.initials: MX
authors.lastname: Li
authors.affiliation: State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China; Department of Molecular Biology and Bioinformatics, College of Life Science, Agricultural University of Hebei, Baoding 071000, China.
authors.forename: Hai-Jing
authors.initials: HJ
authors.lastname: Chang
authors.affiliation: State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China; College of Life Science, Henan Normal University, Xinxiang 453007, China.
authors.forename: Yun
authors.initials: Y
authors.lastname: Mao
authors.affiliation: State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China.
authors.forename: Han-Ying
authors.initials: HY
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China.
authors.forename: Li-Xia
authors.initials: LX
authors.lastname: Lu
authors.affiliation: State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China; College of Life Science, Henan Normal University, Xinxiang 453007, China.
authors.forename: Shuai-Guo
authors.initials: SG
authors.lastname: Yan
authors.affiliation: Department of Molecular Biology and Bioinformatics, College of Life Science, Agricultural University of Hebei, Baoding 071000, China.
authors.forename: Ming-Lin
authors.initials: ML
authors.lastname: Lang
authors.affiliation: State Key Laboratory of Brain and Cognitive Science, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China. Electronic address: liuli@sun5.ibp.ac.cn.
authors.forename: Li
authors.initials: L
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China.
authors.forename: Chuan-Ling
authors.initials: CL
authors.lastname: Qiao
mesh_terms: D000818:Animals; D030801:Animals, Genetically Modified; D001042:Aphids / Q000201:enzymology* / Q000235:genetics; D043182:Carboxylesterase / Q000235:genetics / Q000378:metabolism; D003465:Culex / Q000201:enzymology* / Q000235:genetics; D004331:Drosophila melanogaster / Q000187:drug effects / Q000201:enzymology / Q000235:genetics; D005260:Female; D015870:Gene Expression; D007305:Insecticide Resistance / Q000235:genetics / Q000502:physiology; D007306:Insecticides / Q000494:pharmacology*; D008297:Male; D009154:Mutation; D009570:Nitriles / Q000494:pharmacology; D009943:Organophosphorus Compounds / Q000494:pharmacology; D011722:Pyrethrins / Q000494:pharmacology
chemical_list: D007306:Insecticides; D009570:Nitriles; D009943:Organophosphorus Compounds; D011722:Pyrethrins; C017180:decamethrin; D043182:Carboxylesterase
keywords: Carboxylesterase; Evolution; Insecticide resistance; Mutation; Transgenic Drosophila