title: Caenorhabditis elegans employs innate and learned aversion in response to bacterial toxic metabolites tambjamine and violacein.
abstract: Bacteriovorus eukaryotes such as nematodes are one of the major natural predators of bacteria. In their defense bacteria have evolved a number of strategies to avoid predation, including the production of deterrent or toxic metabolites, however little is known regarding the response of predators towards such bacterial defenses. Here we use the nematode C. elegans as a model to study a predators' behavioral response towards two toxic bacterial metabolites, tambjamine YP1 and violacein. We found that C. elegans displays an innate avoidance behavior towards tambjamine YP1, however requires previous exposure to violacein before learning to avoid this metabolite. The learned avoidance of violacein is specific, reversible, is mediated via the nematode olfactory apparatus (aversive olfactory learning) and is reduced in the absence of the neurotransmitter serotonin. These multiple strategies to evade bacterial toxic metabolites represent a valuable behavioral adaptation allowing bacteriovorus predators to distinguish between good and bad food sources, thus contributing to the understanding of microbial predator-prey interactions.
authors.affiliation: School of Biological, Earth and Environmental Science and Centre for Marine Bio-Innovation, University of New South Wales, Australia.
authors.forename: Francesco
authors.initials: F
authors.lastname: Ballestriero
authors.affiliation: School of Biological, Earth and Environmental Science and Centre for Marine Bio-Innovation, University of New South Wales, Australia.
authors.forename: Jadranka
authors.initials: J
authors.lastname: Nappi
authors.affiliation: Institute of Biosciences and BioResources, National Research Council, Naples, Italy.
authors.forename: Giuseppina
authors.initials: G
authors.lastname: Zampi
authors.affiliation: Institute of Biosciences and BioResources, National Research Council, Naples, Italy.|Institute of Genetics and Biophysics, National Research Council, Naples, Italy.
authors.forename: Paolo
authors.initials: P
authors.lastname: Bazzicalupo
authors.affiliation: Institute of Biosciences and BioResources, National Research Council, Naples, Italy.|Institute of Genetics and Biophysics, National Research Council, Naples, Italy.
authors.forename: Elia
authors.initials: E
authors.lastname: Di Schiavi
authors.affiliation: School of Biological, Earth and Environmental Science and Centre for Marine Bio-Innovation, University of New South Wales, Australia.
authors.forename: Suhelen
authors.initials: S
authors.lastname: Egan
mesh_terms: D000818:Animals; D001362:Avoidance Learning / Q000502:physiology; D001419:Bacteria / Q000378:metabolism*; D017173:Caenorhabditis elegans / Q000502:physiology*; D007211:Indoles / Q000378:metabolism*; D009348:Nematoda / Q000378:metabolism / Q000502:physiology; D018377:Neurotransmitter Agents / Q000378:metabolism; D011235:Predatory Behavior / Q000502:physiology*; D011758:Pyrroles / Q000378:metabolism*; D012903:Smell / Q000502:physiology
chemical_list: D007211:Indoles; D018377:Neurotransmitter Agents; D011758:Pyrroles; C551403:tambjamine K; C063155:violacein