Phylogenetic relationships of a patagonian frog radiation, the Alsodes + Eupsophus clade (Anura, Alsodidae) with comments on the supposed paraphyly of Eupsophus
BLOTTO, B. L.; NUÑEZ, J.J.; BASSO, N.G.; ÚBEDA, C.A.; WHEELER, W.C.; FAIVOVICH, J.
WILEY-BLACKWELL PUBLISHING, INC
Lugar: Londres; Año: 2013 vol. 29 p. 113 - 113
The frog clade composed of the alsodid genera Alsodes + Eupsophus is the most species-rich of the Patagonian endemic frogclades, including nearly 31 of the slightly more than 50 species of that region. The biology of this group of frogs is poorly known, itstaxonomy quite complex (particularly Alsodes), and its diversity in chromosome number striking when compared with other frogs(collectively, there are species having 2n = 22, 2n = 26, 2n = 28, 2n = 30 or 2n = 34). We present a phylogenetic analysis of thisPatagonian frog clade based on mitochondrial and nuclear gene sequences. We sequenced five mitochondrial genes (cytochrome b,cytochrome oxidase I, 12S, 16S, NADH dehydrogenase subunit 1) with three intervening tRNAs, and fragments of three nucleargenes (seven in absentia homolog 1, rhodopsin exon 1, RAG-1), for a maximum of 6510 bp for multiple specimens from 26 of the 31species. We recovered Eupsophus as polyphyletic, with E. antartandicus, E. sylvaticus, and E. taeniatus in Batrachylidae, inaccordance with most previous hypotheses. Based on this result, we transfer E. antartandicus and E. taeniatus back to Batrachyla,and E. sylvaticus to Hylorina (resurrected from the synonymy of Eupsophus), remediating the paraphyly of Eupsophus. Our resultsstrongly corroborate the monophyly of Alsodes + Eupsophus (sensu stricto), the individual monophyly of these genera, and themonophyly of the species groups of Eupsophus. They also show the non-monophyly of all non-monotypic species groups of Alsodesproposed in the past. Our results expose several taxonomic problems particularly in Alsodes, and to a lesser extent in Eupsophus.This phylogenetic context suggests a rich evolutionary history of karyotypic diversification in the clade, in part corroboratingprevious hypotheses. In Alsodes, we predict three independent transformations of chromosome number from the plesiomorphic2n = 26. All these, strikingly, involve increments or reductions of pairs of haploid chromosomes. Finally, the phylogenetic patternrecovered for Alsodes and Eupsophus suggests a trans-Andean origin and diversification of the group, with multiple, independentingressions over cis-Andean regions.