Alytidae - Explore the Science & Experts | ideXlab

Scan Science and Technology

Contact Leading Edge Experts & Companies


The Experts below are selected from a list of 117 Experts worldwide ranked by ideXlab platform

Inigo Martinezsolano – 1st expert on this subject based on the ideXlab platform

  • multilocus phylogeography of the common midwife toad alytes obstetricans anura Alytidae contrasting patterns of lineage diversification and genetic structure in the iberian refugium
    Molecular Phylogenetics and Evolution, 2015
    Co-Authors: Helena Goncalves, Bruno Maiacarvalho, Inigo Martinezsolano, Nuno Ferrand, Tiago Sousaneves, Mario Garciaparis, Fernando Sequeira


    Abstract Recent investigations on the evolutionary history of the common midwife toad (Alytes obstetricans) revealed high levels of geographically structured genetic diversity but also a situation where delineation of major historical lineages and resolution of their relationships are much more complex than previously thought. We studied sequence variation in one mitochondrial and four nuclear genes throughout the entire distribution range of all recognized A. obstetricans subspecies to infer the evolutionary processes that shaped current patterns of genetic diversity and population subdivision. We found six divergent, geographically structured mtDNA haplogroups diagnosing population lineages, and varying levels of admixture in nuclear markers. Given the timeframe inferred for the splits between major lineages, the climatic and environmental changes that occurred during the Pleistocene seem to have shaped the diversification history of A. obstetricans. Survival of populations in allopatric refugia through the Ice Ages supports the generality of the “refugia-within-refugia” scenario for the Iberian Peninsula. However, lineages corresponding to subspecies A. o. almogavarii, A. o. pertinax, A. o. obstetricans, and A. o. boscai responded differently to Pleistocene climatic oscillations after diverging from a common ancestor. Alytes o. obstetricans expanded northward from a northern Iberian refugium through the western Pyrenees, leaving a signal of contrasting patterns of genetic diversity, with a single mtDNA haplotype north of the Pyrenees from SW France to Germany. Both A. o. pertinax and A. o. boscai are widespread and genetically diverse in Iberia, the latter comprising two divergent lineages with a long independent history. Finally, A. o. almogavarii is mostly restricted to the north-eastern corner of Iberia north of the Ebro river, with additional populations in a small region in south-eastern France. This taxon exhibits unparalleled levels of genetic diversity and little haplotype sharing with other lineages, suggesting a process of incipient speciation.

  • multilocus assessment of phylogenetic relationships in alytes anura Alytidae
    Molecular Phylogenetics and Evolution, 2014
    Co-Authors: Bruno Maiacarvalho, Inigo Martinezsolano, Helena Goncalves, Nuno Ferrand


    With the advent of large multilocus datasets, molecular systematics is experiencing very rapid progress, but important challenges remain regarding data analysis and interpretation. Midwife toads (genus Alytes) exemplify two of the most widespread problems for accurate phylogenetic reconstruction: discerning the causes of discordance between gene trees, and resolving short internodes produced during rapid, successive splitting events. The three species in subgenus Baleaphryne (A. maurus, A. dickhilleni and A. muletensis), the sister group to A. obstetricans, have disjunct and highly restricted geographical ranges, which are thought to result from old vicariant events affecting their common ancestor, but their phylogenetic relationships are still unresolved. In this study we re-address the phylogeny of Alytes with a special focus on the relationships in Baleaphryne with a multilocus dataset including >9000 base pairs of mitochondrial DNA and four nuclear markers (3142 bp) in all recognized taxa, including all subspecies of A. obstetricans. Both concatenation and species tree analyses suggest that A. muletensis, endemic to the Balearic island of Mallorca, is the sister taxon to a clade comprising the southeastern Iberian endemic A. dickhilleni and the North African A. maurus. This scenario is consistent with palaeogeological evidence associated with the fragmentation of the Betic-Rifean Massif, followed by the opening of the Strait of Gibraltar. On the other hand, analyses of intraspecific variation in A. obstetricans are inconclusive regarding relationships between major clades and conflict with current subspecific taxonomy.

Michael J Conlon – 2nd expert on this subject based on the ideXlab platform

  • an immunomodulatory peptide related to frenatin 2 from skin secretions of the tyrrhenian painted frog discoglossus sardus Alytidae
    Peptides, 2013
    Co-Authors: Michael J Conlon, Per F Nielsen, Jerome Leprince, Milena Mechkarska, Jelena Pantic, Miodrag L Lukic, Laurent Coquet, Andrea Rinaldi


    Abstract Norepinephrine-stimulated skin secretions of the Tyrrhenian painted frog Discoglossus sardus Tschudi, 1837 (Alytidae) did not contain any peptide with antimicrobial or hemolytic activity. However, peptidomic analysis of the secretions revealed the presence of an abundant peptide with structural similarity to frenatin 2, previously isolated from the Australian frog Litoria infrafrenata (Hylidae). The primary structure of the peptide, termed frenatin 2D, was established as DLLGTLGNLPLPFI.NH 2 by automated Edman degradation and mass spectrometry with electron-transfer dissociation (ETD)-based fragmentation and confirmed by chemical synthesis. The structure of a second frenatin 2-related peptide, termed frenatin 2.1D, that was present in much lower abundance was established as GTLGNLPAPFPG. Frenatin 2D (20 μg/ml) significantly stimulated production of the proinflammatory cytokines TNF-α ( P P P P

  • the alyteserins two families of antimicrobial peptides from the skin secretions of the midwife toad alytes obstetricans Alytidae
    Peptides, 2009
    Co-Authors: Michael J Conlon, Anni Demandt, Per F Nielsen, Jerome Leprince, Hubert Vaudry, Douglas C Woodhams


    Abstract Two families of structurally related C-terminally α-amidated antimicrobial peptides have been identified in norepinephrine-stimulated skin secretions of the midwife toad Alytes obstetricans (Alytidae). The alyteserin-1 peptides (Gly-Leu-Lys-(Asp/Glu)-Ile-Phe-Lys-Ala-Gly-Leu-Gly-Ser-Leu-Val-Lys-(Gly/Asn)-Ile-Ala-Ala-His-Val-Ala-(Asn/Ser).NH 2 ) show limited structural similarity to the ascaphins from the skins of frogs of the family Leiopelmatidae. Alyteserin-2a (Ile-Leu-Gly-Lys-Leu-Leu-Ser-Thr-Ala-Ala-Gly-Leu-Leu-Ser-Asn-Leu.NH 2 ) and alyteserin-2b and -2c (Ile-Leu-Gly-Ala-Ile-Leu-Pro-Leu-Val-Ser-Gly-Leu-Leu-Ser-(Asn/Ser)-Lys-Leu.NH 2 ) show limited sequence identity with bombinin H6, present in the skins of frogs of the family Bombinatoridae. The alyteserin-1 peptides show selective growth inhibitory activity against the Gram-negative bacteria Escherichia coli (MIC = 25 μM) whereas alyteserin-2a is more potent against the Gram-positive bacteria Staphylococcus aureus (MIC = 50 μM). The hemolytic activity against human erythrocytes of all peptides tested is relatively weak (LC 50  > 100 μM). The data demonstrate that the frogs belonging to the family Alytidae are among those producing dermal antimicrobial peptides that may represent a component of the animal’s system of innate immunity.

Borja Sanchiz – 3rd expert on this subject based on the ideXlab platform

  • middle miocene remains of alytes anura Alytidae as an example of the unrecognized value of fossil fragments for evolutionary morphology studies
    Journal of Vertebrate Paleontology, 2014
    Co-Authors: Markus Bastir, Madelaine Bohme, Borja Sanchiz


    ABSTRACT. Fragmentary anuran remains (an ilium and radioulna) from the middle Miocene of Moratilla 2 (Teruel Province, Spain) are identified, using qualitative characters and geometric morphometrics, as belonging to a new unnamed species of midwife toad, of the extant anuran genus Alytes (Alytidae). The Moratilla 2 fossils of Alytes are dated to ca. 16–17 Ma, prior to the early splits that resulted in the current Alytes diversification. Our biometric study of the fossil radioulnar fragment, an element usually considered uninformative, has revealed convergent adaptive trends in forearm locomotor performance within the genus. This finding would have remained hidden otherwise, because neither molecular approaches nor the comparative osteology of living forms would have detected it. A model for the evolutionary history of midwife toads is proposed, as a case example of how molecular phylogeographic results can be combined with morphological and paleontological studies at the genus level. Historical models of …

  • ultrafast evolutionary morphological change in the mallorca midwife toad alytes muletensis Alytidae
    , 2010
    Co-Authors: Markus Bastir, Josep Antoni Alcover, Borja Sanchiz


    Trabajo presentado en el XI Congreso Luso – Espanol de Herpetologia / XV Congreso Espanol de Herpetologia, celebrado en Sevilla, Espana, del 6 al 9 de octubre de 2010