title: Venom toxicity and composition in three Pseudomyrmex ant species having different nesting modes.
abstract: We aimed to determine whether the nesting habits of ants have influenced their venom toxicity and composition. We focused on the genus Pseudomyrmex (Pseudomyrmecinae) comprising terrestrial and arboreal species, and, among the latter, plant-ants that are obligate inhabitants of myrmecophytes (i.e., plants sheltering ants in hollow structures). Contrary to our hypothesis, the venom of the ground-dwelling species, Pseudomyrmex termitarius, was as efficacious in paralyzing prey as the venoms of the arboreal and the plant-ant species, Pseudomyrmex penetrator and Pseudomyrmex gracilis. The lethal potency of P. termitarius venom was equipotent with that of P. gracilis whereas the venom of P. penetrator was less potent. The MALDI-TOF MS analysis of each HPLC fraction of the venoms showed that P. termitarius venom is composed of 87 linear peptides, while both P. gracilis and P. penetrator venoms (23 and 26 peptides, respectively) possess peptides with disulfide bonds. Furthermore, P. penetrator venom contains three hetero- and homodimeric peptides consisting of two short peptidic chains linked together by two interchain disulfide bonds. The large number of peptides in P. termitarius venom is likely related to the large diversity of potential prey plus the antibacterial peptides required for nesting in the ground. Whereas predation involves only the prey and predator, P. penetrator venom has evolved in an environment where trees, defoliating insects, browsing mammals and ants live in equilibrium, likely explaining the diversity of the peptide structures.
authors.affiliation: CNRS, UMR Ecologie des Forêts de Guyane (EcoFoG), Campus Agronomique, BP 316, 97379 Kourou Cedex, France.
authors.forename: Axel
authors.initials: A
authors.lastname: Touchard
authors.affiliation: CNRS, UMR Ecologie des Forêts de Guyane (EcoFoG), Campus Agronomique, BP 316, 97379 Kourou Cedex, France.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Labrière
authors.affiliation: IRD, MIVEGEC (IRD 224-CNRS 5290-UM1-UM2) Équipe BEES, 911 Avenue Agropolis, BP 64501, 34394 Montpellier Cedex 5, France.
authors.forename: Olivier
authors.initials: O
authors.lastname: Roux
authors.affiliation: CNRS, UMR Ecologie des Forêts de Guyane (EcoFoG), Campus Agronomique, BP 316, 97379 Kourou Cedex, France.
authors.forename: Frédéric
authors.initials: F
authors.lastname: Petitclerc
authors.affiliation: CNRS, UMR Ecologie des Forêts de Guyane (EcoFoG), Campus Agronomique, BP 316, 97379 Kourou Cedex, France.
authors.forename: Jérôme
authors.initials: J
authors.lastname: Orivel
authors.affiliation: VenomeTech, 473 Route des Dolines-Villa 3, Valbonne 06560, France.
authors.forename: Pierre
authors.initials: P
authors.lastname: Escoubas
authors.affiliation: Neurotoxin Research Group, School of Medical & Molecular Biosciences, University of Technology, Sydney, Broadway NSW, 2007, Australia.
authors.forename: Jennifer M S
authors.initials: JM
authors.lastname: Koh
authors.affiliation: Neurotoxin Research Group, School of Medical & Molecular Biosciences, University of Technology, Sydney, Broadway NSW, 2007, Australia.
authors.forename: Graham M
authors.initials: GM
authors.lastname: Nicholson
authors.affiliation: CNRS, UMR Ecologie des Forêts de Guyane (EcoFoG), Campus Agronomique, BP 316, 97379 Kourou Cedex, France; Laboratoire Écologie Fonctionnelle et Environnement, 118 Route de Narbonne, 31062 Toulouse, France. Electronic address: alain.dejean@wanadoo.fr.
authors.forename: Alain
authors.initials: A
authors.lastname: Dejean
mesh_terms: D000818:Animals; D000862:Ant Venoms / Q000032:analysis / Q000737:chemistry / Q000633:toxicity*; D001000:Ants; D002851:Chromatography, High Pressure Liquid; D008970:Molecular Weight; D009425:Nesting Behavior; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
chemical_list: D000862:Ant Venoms
keywords: Ant venoms; Ants; Arboreal and ground-nesting ants; Evolution; Peptides; Pseudomyrmex