title: Induced thiacloprid insensitivity in honeybees (Apis mellifera L.) is associated with up-regulation of detoxification genes.
abstract: Honey bees, Apis mellifera, are markedly less sensitive to neonicotinoid insecticides containing a cyanoimino pharmacophore than to those with a nitroimino group. Although previous work has suggested that this results from enhanced metabolism of the former by detoxification enzymes, the specific enzyme(s) involved remain to be characterized. In this work, a pretreatment of honey bees with a sublethal dose of thiacloprid resulted in induced insensitivity to the same compound immediately following thiacloprid feeding. A longer pretreatment time resulted in no, or increased, sensitivity. Transcriptome profiling, using microarrays, identified a number of genes encoding detoxification enzymes that were over-expressed significantly in insecticide-treated bees compared with untreated controls. These included five P450s, CYP6BE1, CYP305D1, CYP6AS5, CYP315A1, CYP301A1, and a carboxyl/cholinesterase (CCE) CCE8. Four of these P450s were functionally expressed in Escherichia coli and their ability to metabolize thiacloprid examined by liquid chromatography-mass spectrometry (LC-MS) analysis.
authors.affiliation: Department of Biological Chemistry and Crop Protection, Rothamsted Research, Harpenden, UK.
authors.forename: S
authors.initials: S
authors.lastname: Alptekin
authors.affiliation: Department of Biological Chemistry and Crop Protection, Rothamsted Research, Harpenden, UK.
authors.forename: C
authors.initials: C
authors.lastname: Bass
authors.affiliation: AHDB, Stoneleigh Park, Kenilworth, Warwickshire, UK.
authors.forename: C
authors.initials: C
authors.lastname: Nicholls
authors.affiliation: Department of Vector Biology, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, UK.
authors.forename: M J I
authors.initials: MJ
authors.lastname: Paine
authors.affiliation: Department of Biological Chemistry and Crop Protection, Rothamsted Research, Harpenden, UK.
authors.forename: S J
authors.initials: SJ
authors.lastname: Clark
authors.affiliation: Department of Biological Chemistry and Crop Protection, Rothamsted Research, Harpenden, UK.
authors.forename: L
authors.initials: L
authors.lastname: Field
authors.affiliation: ApresLabs Ltd, Research and Innovation Campus, Rothamsted, Harpenden, UK.
authors.forename: G D
authors.initials: GD
authors.lastname: Moores
mesh_terms: D000691:Anabasine / Q000494:pharmacology; D000818:Animals; D001516:Bees / Q000187:drug effects* / Q000378:metabolism; D003577:Cytochrome P-450 Enzyme System / Q000187:drug effects / Q000235:genetics*; D005786:Gene Expression Regulation / Q000187:drug effects; D008658:Inactivation, Metabolic / Q000235:genetics*; D007306:Insecticides / Q000494:pharmacology; D000073943:Neonicotinoids; D011725:Pyridines / Q000494:pharmacology; D013843:Thiazines / Q000494:pharmacology; D015533:Transcriptional Activation / Q000187:drug effects
chemical_list: D007306:Insecticides; D000073943:Neonicotinoids; D011725:Pyridines; D013843:Thiazines; D003577:Cytochrome P-450 Enzyme System; C417209:thiacloprid; D000691:Anabasine
keywords: Apis mellifera; P450; esterase; induction; metabolism; thiacloprid