title: Nuclear and mitochondrial multilocus phylogeny and survey of alkaloid content in true salamanders of the genus Salamandra (Salamandridae).
abstract: The genus Salamandra represents a clade of six species of Palearctic salamanders of either contrasted black-yellow, or uniformly black coloration, known to contain steroidal alkaloid toxins in high concentrations in their skin secretions. This study reconstructs the phylogeny of the genus Salamandra based on DNA sequences of segments of 10 mitochondrial and 13 nuclear genes from 31 individual samples representing all Salamandra species and most of the commonly recognized subspecies. The concatenated analysis of the complete dataset produced a fully resolved tree with most nodes strongly supported, suggesting that a clade composed of the Alpine salamander (S. atra) and the Corsican fire salamander (S. corsica) is the sister taxon to a clade containing the remaining species, among which S. algira and S. salamandra are sister species. Separate analyses of mitochondrial and nuclear data partitions disagreed regarding basal nodes and in the position of the root but concordantly recovered the S. atra/S. corsica as well as the S. salamandra/S. algira relationship. A species-tree analysis suggested almost simultaneous temporal splits between these pairs of species, which we hypothesize was caused by vicariance events after the Messinian salinity crisis (from late Miocene to early Pliocene). A survey of toxins with combined gas chromatography/mass spectroscopy confirmed the presence of samandarine and/or samandarone steroidal alkaloids in all species of Salamandra as well as in representatives of their sister group, Lyciasalamandra. Samandarone was also detected in lower concentrations in other salamandrids including Calotriton, Euproctus, Lissotriton, and Triturus, suggesting that the presence and possible biosynthesis of this alkaloid is plesiomorphic within the Salamandridae.
authors.affiliation: Zoological Institute, Technische Universität Braunschweig, Mendelssohnstr. 4, 38106 Braunschweig, Germany. Electronic address: m.vences@tu-bs.de.
authors.forename: Miguel
authors.initials: M
authors.lastname: Vences
authors.affiliation: Zoological Institute, Technische Universität Braunschweig, Mendelssohnstr. 4, 38106 Braunschweig, Germany; Laboratorio de Sistemática Molecular, Universidad Simón Bolívar, Caracas, Venezuela.
authors.forename: Eugenia
authors.initials: E
authors.lastname: Sanchez
authors.affiliation: Zoological Institute, Technische Universität Braunschweig, Mendelssohnstr. 4, 38106 Braunschweig, Germany.
authors.forename: J Susanne
authors.initials: JS
authors.lastname: Hauswaldt
authors.affiliation: Zoological Institute, Technische Universität Braunschweig, Mendelssohnstr. 4, 38106 Braunschweig, Germany.
authors.forename: Daniel
authors.initials: D
authors.lastname: Eikelmann
authors.affiliation: Zoological Institute, Technische Universität Braunschweig, Mendelssohnstr. 4, 38106 Braunschweig, Germany.
authors.forename: Ariel
authors.initials: A
authors.lastname: Rodríguez
authors.affiliation: Institute of Evolutionary Biology (CSIC-UPF), Passeig Marítim de la Barceloneta, 37-49, 08003 Barcelona, Spain.
authors.forename: Salvador
authors.initials: S
authors.lastname: Carranza
authors.affiliation: Asociación Herpetológica Fretum Gaditanum.Calle Mar Egeo 7, 11407 Jerez de la Frontera, Cádiz, Spain.
authors.forename: David
authors.initials: D
authors.lastname: Donaire
authors.affiliation: DBEZ-Centro de Biociências, Universidade Federal do Rio Grande do Norte, Campus Universitário Lagoa Nova, 59078-900 Natal, RN, Brazil.
authors.forename: Marcelo
authors.initials: M
authors.lastname: Gehara
authors.affiliation: Department of Organismic Biology, Faculty of Natural Sciences, University of Salzburg, Hellbrunnerstrasse 34, 5020 Salzburg, Austria.
authors.forename: Véronique
authors.initials: V
authors.lastname: Helfer
authors.affiliation: Biogeography Department, Trier University, 54286 Trier, Germany.
authors.forename: Stefan
authors.initials: S
authors.lastname: Lötters
authors.affiliation: Biogeography Department, Trier University, 54286 Trier, Germany.
authors.forename: Philine
authors.initials: P
authors.lastname: Werner
authors.affiliation: Institute of Organic Chemistry, Technische Universität Braunschweig, Hagenring 30, 38106 Braunschweig, Germany.
authors.forename: Stefan
authors.initials: S
authors.lastname: Schulz
authors.affiliation: Zoological Institute, Technische Universität Braunschweig, Mendelssohnstr. 4, 38106 Braunschweig, Germany.
authors.forename: Sebastian
authors.initials: S
authors.lastname: Steinfartz
mesh_terms: D000470:Alkaloids / Q000032:analysis*; D000731:Androstanes / Q000032:analysis / Q000737:chemistry; D000818:Animals; D001378:Azasteroids / Q000032:analysis / Q000737:chemistry; D002467:Cell Nucleus / Q000235:genetics*; D004272:DNA, Mitochondrial / Q000235:genetics*; D056426:Genetic Loci / Q000235:genetics*; D006239:Haplotypes / Q000235:genetics; D019083:Mediterranean Region; D010802:Phylogeny; D058974:Phylogeography; D012454:Salamandra / Q000145:classification / Q000235:genetics* / Q000378:metabolism*; D017422:Sequence Analysis, DNA; D014118:Toxins, Biological / Q000032:analysis / Q000737:chemistry
chemical_list: D000470:Alkaloids; D000731:Androstanes; D001378:Azasteroids; D004272:DNA, Mitochondrial; D014118:Toxins, Biological; C025055:samandarone
keywords: Amphibia; Caudata; Mediterranean biogeography; Salamandridae; Species tree; Steroidal toxins