title: Chemical camouflage--a frog's strategy to co-exist with aggressive ants.
abstract: Whereas interspecific associations receive considerable attention in evolutionary, behavioural and ecological literature, the proximate bases for these associations are usually unknown. This in particular applies to associations between vertebrates with invertebrates. The West-African savanna frog Phrynomantis microps lives in the underground nest of ponerine ants (Paltothyreus tarsatus). The ants usually react highly aggressively when disturbed by fiercely stinging, but the frog is not attacked and lives unharmed among the ants. Herein we examined the proximate mechanisms for this unusual association. Experiments with termites and mealworms covered with the skin secretion of the frog revealed that specific chemical compounds seem to prevent the ants from stinging. By HPLC-fractionation of an aqueous solution of the frogs' skin secretion, two peptides of 1,029 and 1,143 Da were isolated and found to inhibit the aggressive behaviour of the ants. By de novo sequencing using tandem mass spectrometry, the amino acid sequence of both peptides consisting of a chain of 9 and 11 residues, respectively, was elucidated. Both peptides were synthesized and tested, and exhibited the same inhibitory properties as the original frog secretions. These novel peptides most likely act as an appeasement allomone and may serve as models for taming insect aggression.
authors.affiliation: Museum für Naturkunde Berlin, Leibniz Institute for Research on Evolution and Biodiversity, Berlin, Germany ; Theodor-Boveri-Institute (Biocenter of the University), Department of Animal Ecology and Tropical Biology (Zoology III), Würzburg, Germany.
authors.forename: Mark-Oliver
authors.initials: MO
authors.lastname: Rödel
authors.affiliation: Theodor-Boveri-Institute (Biocenter of the University), Department of Animal Ecology and Tropical Biology (Zoology III), Würzburg, Germany ; Medizinische Klinik und Poliklinik II, Zentrum für Experimentelle Molekulare Medizin, Würzburg, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Brede
authors.affiliation: Museum für Naturkunde Berlin, Leibniz Institute for Research on Evolution and Biodiversity, Berlin, Germany ; Theodor-Boveri-Institute (Biocenter of the University), Department of Animal Ecology and Tropical Biology (Zoology III), Würzburg, Germany.
authors.forename: Mareike
authors.initials: M
authors.lastname: Hirschfeld
authors.affiliation: Theodor-Boveri-Institute (Biocenter of the University), Department of Animal Ecology and Tropical Biology (Zoology III), Würzburg, Germany ; Ecological Networks, Biology, Technische Universität Darmstadt, Darmstadt, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Schmitt
authors.affiliation: Atheris Laboratories, Bernex, Switzerland.
authors.forename: Philippe
authors.initials: P
authors.lastname: Favreau
authors.affiliation: Atheris Laboratories, Bernex, Switzerland.
authors.forename: Reto
authors.initials: R
authors.lastname: Stöcklin
authors.affiliation: Institute of Legal Medicine, University of Frankfurt, Frankfurt/M., Germany.
authors.forename: Cora
authors.initials: C
authors.lastname: Wunder
authors.affiliation: Institute of Legal Medicine, University of Frankfurt, Frankfurt/M., Germany.
authors.forename: Dietrich
authors.initials: D
authors.lastname: Mebs
mesh_terms: D000374:Aggression / Q000187:drug effects; D029845:Amphibian Proteins / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology*; D000818:Animals; D001000:Ants / Q000187:drug effects* / Q000502:physiology; D001001:Anura / Q000502:physiology*; D001522:Behavior, Animal / Q000187:drug effects; D017753:Ecosystem; D009842:Oligopeptides / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology*; D010675:Pheromones / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology*; D012867:Skin / Q000378:metabolism; D053719:Tandem Mass Spectrometry
chemical_list: D029845:Amphibian Proteins; D009842:Oligopeptides; D010675:Pheromones