title: Concentration-dependent effects of acute and chronic neonicotinoid exposure on the behaviour and development of the nematode Caenorhabditis elegans.
abstract: BACKGROUND
  Neonicotinoid insecticides are under review owing to emerging toxicity to non-target species. Interest has focused on biological pollinators while their effects on other organisms that are key contributors to the ecosystem remain largely unknown. To advance this, we have tested the effects of representatives of three major classes of neonicotinoids, thiacloprid, clothianidin and nitenpyram, on the free-living nematode Caenorhabditis elegans (C. elegans), as a representative of the Nematoda, an ecologically important phylum contributing to biomass.
  
  
  RESULTS
  Concentrations that are several-fold higher than those with effects against target species had limited impact on locomotor function. However, increased potency was observed in a mutant with a hyperpermeable cuticle, which shows that drug access limits the effects of the neonicotinoids in C. elegans. Thiacloprid was most potent (EC50714 μm). In addition, it selectively delayed larval development in wild-type worms at 1 mm.
  
  
  CONCLUSIONS
  C. elegans is less susceptible to neonicotinoids than target species of pest insect. We discuss an approach in which this defined low sensitivity may be exploited by heterologous expression of insect nicotinic acetylcholine receptors from both pest and beneficial insects in transgenic C. elegans with increased cuticle permeability to provide a whole organism assay for species-dependent neonicotinoid effects. © 2017 Society of Chemical Industry.
authors.affiliation: Biological Sciences, University of Southampton, Southampton, UK.
authors.forename: Monika M
authors.initials: MM
authors.lastname: Kudelska
authors.affiliation: Biological Sciences, University of Southampton, Southampton, UK.
authors.forename: Lindy
authors.initials: L
authors.lastname: Holden-Dye
authors.affiliation: Biological Sciences, University of Southampton, Southampton, UK.
authors.forename: Vincent
authors.initials: V
authors.lastname: O'Connor
authors.affiliation: Biological Sciences, University of Southampton, Southampton, UK.
authors.forename: Declan A
authors.initials: DA
authors.lastname: Doyle
mesh_terms: D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects; D017173:Caenorhabditis elegans / Q000187:drug effects* / Q000235:genetics / Q000254:growth & development; D007306:Insecticides / Q000633:toxicity*; D034582:Integumentary System / Q000473:pathology; D007814:Larva / Q000187:drug effects; D008124:Locomotion / Q000187:drug effects; D000073943:Neonicotinoids / Q000633:toxicity*; D009538:Nicotine / Q000008:administration & dosage / Q000494:pharmacology; D010539:Permeability
chemical_list: D007306:Insecticides; D000073943:Neonicotinoids; D009538:Nicotine
keywords: bus-17; nicotine; nicotinic acetylcholine receptors; thiacloprid; toxicity