title: The cys-loop ligand-gated ion channel gene family of Tetranychus urticae: implications for acaricide toxicology and a novel mutation associated with abamectin resistance.
abstract: The cys-loop ligand-gated ion channel (cysLGIC) super family of Tetranychus urticae, the two-spotted spider mite, represents the largest arthropod cysLGIC super family described to date and the first characterised one within the group of chelicerates. Genome annotation, phylogenetic analysis and comparison of the cysLGIC subunits with their counterparts in insects reveals that the T. urticae genome encodes for a high number of glutamate- and histamine-gated chloride channel genes (GluCl and HisCl) compared to insects. Three orthologues of the insect γ-aminobutyric acid (GABA)-gated chloride channel gene Rdl were detected. Other cysLGIC groups, such as the nAChR subunits, are more conserved and have clear insect orthologues. Members of cysLGIC family mediate endogenous chemical neurotransmission and they are prime targets of insecticides. Implications for toxicology associated with the identity and specific features of T. urticae family members are discussed. We further reveal the accumulation of known and novel mutations in different GluCl channel subunits (Tu_GluCl1 and Tu_GluCl3) associated with abamectin resistance in T. urticae, and provide genetic evidence for their causality. Our study provides useful toxicological insights for the exploration of the T. urticae cysLGIC subunits as putative molecular targets for current and future chemical control strategies.
authors.affiliation: Laboratory of Agrozoology, Department of Crop Protection, Faculty of Agricultural and Applied, Biological Sciences, Ghent University, Coupure Links 653, B-9000 Ghent, Belgium. wannes.dermauw@ugent.be
authors.forename: W
authors.initials: W
authors.lastname: Dermauw
authors.forename: A
authors.initials: A
authors.lastname: Ilias
authors.forename: M
authors.initials: M
authors.lastname: Riga
authors.forename: A
authors.initials: A
authors.lastname: Tsagkarakou
authors.forename: M
authors.initials: M
authors.lastname: Grbić
authors.forename: L
authors.initials: L
authors.lastname: Tirry
authors.forename: T
authors.initials: T
authors.lastname: Van Leeuwen
authors.forename: J
authors.initials: J
authors.lastname: Vontas
mesh_terms: D056810:Acaricides / Q000494:pharmacology*; D000595:Amino Acid Sequence; D000818:Animals; D060829:Arthropod Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D001483:Base Sequence; D018118:Chloride Channels / Q000737:chemistry / Q000235:genetics; D058466:Cysteine Loop Ligand-Gated Ion Channel Receptors / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D004351:Drug Resistance; D019476:Insect Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D007313:Insecta / Q000235:genetics / Q000378:metabolism; D007559:Ivermectin / Q000031:analogs & derivatives* / Q000494:pharmacology; D058977:Molecular Sequence Annotation; D008969:Molecular Sequence Data; D005810:Multigene Family; D009154:Mutation; D010802:Phylogeny; D016133:Polymerase Chain Reaction; D021122:Protein Subunits / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D016415:Sequence Alignment; D040102:Tetranychidae / Q000145:classification / Q000187:drug effects* / Q000235:genetics* / Q000378:metabolism
chemical_list: D056810:Acaricides; D060829:Arthropod Proteins; D018118:Chloride Channels; D058466:Cysteine Loop Ligand-Gated Ion Channel Receptors; D019476:Insect Proteins; D021122:Protein Subunits; C048324:abamectin; D007559:Ivermectin