The phylogenetic position of the enigmatic Atlantic forest-endemic spiny mouse Abrawayaomys (Rodentia: Sigmodontinae)

Karen Ventura,Maria José J Silva,Ulyses Fj Pardiñas,Yuri Lr Leite,Lena Geise,Guillermo D'Elía,Yatiyo Yonenaga-Yassuda

doi:10.1186/1810-522x-52-55

Abstract

AbstractBackgroundThe phylogenetic position of the sigmodontine genusAbrawayaomys, historically assigned to the tribe Thomasomyini or considered a sigmodontine incertae sedis, was assessed on the basis of nuclear and mitochondrial DNA sequences obtained from four individuals from different localities in the Atlantic forest of Brazil. Sequences ofAbrawayaomyswere analyzed in the context of broad taxonomic matrices by means of maximum-likelihood (ML) and Bayesian analyses (BA).ResultsThe phylogenetic position ofAbrawayaomysdiffered depending on the gene analyzed and the analysis performed (interphotoreceptor retinoid-binding protein (IRBP) ML: sister to Thomasomyini; IRBP BA: sister to Akodontini; cytochrome (Cyt)bML: sister toNeotomys; and CytbBA: sister to Reithrodontini). With the sole exception of the BA based on Cytbsequences, where theAbrawayaomys-Reithrodonclade had strong support, all sister-group relationships involvingAbrawayaomyslacked any significant support.ConclusionsAs such,Abrawayaomysconstitutes the only representative so far known of one of the main lineages of the sigmodontine radiation, differing from all other Atlantic forest sigmodontine rodents by having a unique combination of morphological character states. Therefore, in formal classifications, it should be regarded as a Sigmodontinae incertae sedis.

Highlights

The phylogenetic position of the sigmodontine genus Abrawayaomys, historically assigned to the tribe Thomasomyini or considered a sigmodontine incertae sedis, was assessed on the basis of nuclear and mitochondrial DNA sequences obtained from four individuals from different localities in the Atlantic forest of Brazil
Cyt b gene sequences of Abrawayaomys gathered from the three specimens collected in the states of São Paulo and Rio de Janeiro varied by 0.5% ~ 0.7%; while comparisons involving the Cyt b sequence of the specimen from Minas Gerais ranged 2.6% ~ 3.0%
For descriptions and discussions of these findings, we refer the reader to those studies because we focus on the phylogenetic position of Abrawayaomys

Summary

Introduction

The phylogenetic position of the sigmodontine genus Abrawayaomys, historically assigned to the tribe Thomasomyini or considered a sigmodontine incertae sedis, was assessed on the basis of nuclear and mitochondrial DNA sequences obtained from four individuals from different localities in the Atlantic forest of Brazil. In the last two decades, phylogenetic analyses using either morphological or molecular data or both were used to set the limits and contents of these groups and determine the timing of their diversification (e.g., Braun 1993; Smith and Patton 1999; Steppan 1995; D'Elía 2003b; Pacheco 2003; Weksler 2003; D'Elía et al 2003, D'Elia et al 2006a, b; Martínez et al 2012; Parada et al 2013; Salazar-Bravo et al 2013). 12 extant genera are considered as Sigmodontinae incertae sedis (see the most recently published classification in D'Elía et al (2007) and the modification prompted by the description of a new genus by Alvarado-Serrano and D'Elía (2013)); one of these is Abrawayaomys Cunha and Cruz 1979

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Conclusion