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The issue of whether Proedromys should be included in the genus Micritus or considered a valid genus has been a controversial issue, since it was established that the genus Proedromys contained only a single species (Proedromys bedfordi). In 2007, a vole species of Proedromys (Proedromys liangshanensis) was identified. In order to elaborate the phylogenetic positions of the genus Proedromys and the vole species, we determined mitochondrial (cyt b) and two unclear (GHR and IRBP) DNA fragments. Bayesian inference and Maximum likelihood analyses based on a combined matrix indicated that Proedromys is not monophyletic as it is currently recognized. P. bedfordi was separated from the genus Microtus, forming a well-supported clade and was a sister taxon to Volemys musseri. The position of P. liangshanensis, however, was unstable due to low/moderately supported value. Molecular dating analyses using BEAST suggested an early Pleistocene origin for the genus.

A vole species, Proedromys liangshanensis Liu, Sun, Zeng and Zhao, 2007 (Rodentia: Arvicolinae), which is endemic to the Liangshan Mountains, Sichuan, China, was reported in 2007. The species is restricted to a narrow range because of its weak dispersal ability and habitat specificity, and only lives in fir and spruce forests with abundant grass. In this study, the genetic diversity and phylogeographical structure of 42 P. liangshanensis were examined based on analysis of a partial mitochondrial DNA control region. The results revealed low genetic diversity in the P. liangshanensis populations. Twelve nucleotide haplotypes were defined in the 42 collected individuals, and were divided into two major phylogenetic clades, which were obviously related to geographic pattern. Estimates of gene flow (Nm = 0.09) also revealed a genetic divergence between the Jinyang and Meigu populations. Species-specific traits, habitat specificity and geographic events contributed to the genetic divergence of the new vole.

The Chinese oriental vole (Eothenomys chinensis) belongs to subfamily Arvicolinae, which is endemic to the mountains in southwest China. E. chinensis and other Arvicoline species display a number of features that make them ideal for evolutionary studies of speciation and the role of Quaternary glacial cycles on diversification. In this study, the complete mitochondrial genome of E. chinensis was sequenced. It was determined to be 16,362 bases. The nucleotide sequence data of 12 heavy-strand protein-coding genes of E. chinensis and other 19 rodents were used for phylogenetic analyses. Trees constructed using three different phylogenetic methods (Bayesian, maximum parsimony, and maximum likelihood) showed a similar topology demonstrating that E. chinensis was clustered in subfamily arvicolinae--formed a solid monophyletic group being sister to the subfamily Cricetinae. And the trees also suggested that E. chinensis is a sister to the genus Microtus and Proedromys.

China has 26 species in the tribe Arvicolini. The taxonomic status of these voles remains controversial despite much effort. Herein, we evaluate the taxonomic position of 22 species plus 2 unidentified taxa using mitochondrial DNA gene sequences (cytb + CO1). We also evaluate 18 species and 2 unidentified taxa using morphological data. Phylogenetic analyses of cytb resolve monophyly for the genera Alexandromys, Lasiopodomys, Microtus, Neodon, Proedromys, and Volemys with strong support. Stenocranius clusters with Chionomys but with very weak support. Analyses of concatenated cytb + CO1 resolve the same genera with strong support, but the topology of the tree differs from that of cytb in that Chionomys roots at the base of the tree independent of Stenocranius, which forms the sister-group of Lasiopodomys in a more terminal position. The matrilineal genealogy excludes the type species Arvicola amphibius from the rest of the Arvicolini. This species forms the sister-group of Ondatra with high support. Neodon includes N. irene, N. linzhiensis, N. fuscus, N. leucurus, N. sikimensis, Microtus clarkei, and 2 unidentified specimens. Alexandromys includes the former species Microtus oeconomus, M. kikuchii, M. limnophilus, M. fortis, and M. maximowiczii. Finally, Microtus has the subgenera Blanfordimys, Microtus, Mynomes, Pedomys, Pitymys, and Terricola, which includes the Chinese species M. agrestis, M. arvalis, and Blanfordimys juldaschi. General mixed Yule-coalescent species delimitation modeling demarcates 6 currently recognized species and 2 new species of Neodon. A principal component analysis of the morphological data among 7 matrilines shows that all variables have positive loadings of high magnitude on the 1st component. Canonical discriminant analysis for Neodon (including M. clarkei and 2 unidentified species) correctly classifies 93.0% of specimens. Overall, our analyses support the recognition of Alexandromys, Lasiopodomys, Microtus, Neodon, Proedromys, and Volemys as genera. Stenocranius includes Microtus gregalis, and the genealogical position of Stenocranius remains uncertain. The status of Arvicola requires further study. We assign M. clarkei to Neodon and describe 2 new species of Neodon.

AIM. The complete mitochondrial genome sequence of a newly discovered vole, Proedromys liangshanensis (Rodentia: Cricetidae: Arvicolinae), was determined. RESULTS. The mitogenome of P. liangshanensis is 16,296 bp in length. As with most other mammals, it contains the same gene order and an identical number of genes or regions, including 13 protein-coding genes, two ribosomal RNA genes, 22 transfer RNA genes, and one putative control region. The A+T content of the control region is 58.2%, the lowest proportion detected so far in Myomorpha. To confirm the phylogenetic position of P. liangshanensis, we carried out phylogenetic analyses based on complete mitochondrial genomic data using Bayesian, maximum parsimony, and maximum likelihood methods. CONCLUSION. All results revealed that P. liangshanenis is sister to Microtus. Although the results do not bear light on the validity of the genus Proedromys, based on the morphological characters, we suggest that Proedromys is an independent genus of equal rank to the genus Microtus.