Mitochondrial phylogeny of Arvicolinae using comprehensive taxonomic sampling yields new insights

Abstract

Comprehensive taxonomic sampling can vastly improve the accuracy of phylogenetic reconstruction. Here, we present the most inclusive phylogenetic analysis of Arvicolinae (Mammalia, Rodentia) to date, combining all published cytochrome b gene sequences of greater than 1097 bp and new sequences from two monotypic genera. Overall, the phylogenetic relationships between 69 species of voles and lemmings, representing 18 genera and 10 tribes, were studied. By applying powerful modern approaches to phylogenetic reconstruction, such as maximum likelihood and Bayesian analysis, we provide new information on the early pulse of evolution within the Arvicolinae. While the position of two highly divergent lineages, Phenacomys and Ondatra, could not be resolved, the tribe Lemmini, appeared as the most basal group of voles. The collared lemmings (Dicrostonychini) grouped together with all of the remaining tribes. The two previously unstudied monotypic genera Dinaromys and Prometheomys form a moderately well-supported monophyletic clade, possibly a sister group to Ellobius (Ellobiusini). Furthermore, with one exception, all tribes (sensu Musser & Carleton, 2005) proved to be monophyletic and can thus be regarded as meaningful evolutionary entities. Only the tribe Arvicolini emerged as paraphyletic in both analyses because of the unresolved phylogenetic position of Arvicola terrestris. Steppe voles of the genus Lagurus were solidly supported as a sister group to the Microtus and allies clade.

New insights into the taxonomy and phylogeny of social voles inferred from mitochondrial cytochrome b sequences

“…The average ratio of transitions/transversions was 4.5. Nucleotide composition was characterized by a deficit of guanines (13.08%), similar to previous findings in arvicolins (Buzan et al, 2008) and mammals (Irwin et al, 1991).…”

A novel sex determination system in a close relative of the house mouse

“…The genetic bases of these modifications are all unknown, but are associated with an X-linked mutation in Myopus (deletion of Xp 21 -23 ; Liu et al 1998), and possibly so too in Dicrostonyx and Akodon (Fredga 1988;Ortiz et al 2009). Although these mutations have appeared independently in the four different lineages (even the two lemmings are not closely related; Buzan et al 2008), they are all X-linked, and may therefore involve the same gene(s). Clearly, further molecular/genomic analyses are required in M. minutoides to identify the mutational event changing the normal X chromosome into the derivative X*.…”

Mitochondrial phylogeography of the European ground squirrel, Spermophilus citellus, yields evidence on refugia for steppic taxa in the southern Balkans

“…As the first 10% of trees were discarded as 'burn-in,' only the last 180 000 trees were used to compute the 50%, majority rule consensus tree. Bayesian posterior probabilities (BPP) were used to assess branch support of the BI tree; we considered a BPP 40.90 as the cutoff for 'moderate' support (Buzan et al, 2008).…”