Mole rats (genus Nannospalax) display prolific chromosomal variation with more than 50 distinct cytotypes. These cytotypes are largely indistinguishable morphologically, are mainly allopatric and their taxonomic ranking is contradictory. We established a cytochrome b phylogeny for 15 cytotypes belonging to all three species recognized on morphological grounds (morphospecies): N. leucodon, N. xanthodon and N. ehrenbergi. Phylogenetic reconstructions yielded two highly divergent groups which are in agreement with the current division into two subgenera (Nannospalax and Mesospalax). The former comprised samples from south-eastern Turkey, Israel and Egypt (the morphospecies N. ehrenbergi). Basal dichotomy within Mesospalax remained unresolved and the putative sister position of N. leucodon against the two lineages of N. xanthodon was not supported in our analysis. Net divergences between sister cytotypes were low (< 2.0%) and two N. leucodon cytotypes were not even reciprocally monophyletic. Among the three morphospecies, the genetic diversity was lowest in N. leucodon (2.4% ± 0.3%), highest in N. xanthodon (8.8% ± 0.7%) and intermediate in N. ehrenbergi (5.0% ± 0.5%). Our results show that associations between genetic and chromosomal variation are not widespread and common in mole rats, and therefore refute the generalization of a 'cytotype-equals-species' approach.

a b s t r a c tIn this study, the 2n = 40, 58, 60 chromosome races of mole rats of the Nannospalax nehringi superspecies from the Konya province in Turkey were investigated. Conventional chromosome staining, Ag-NOR staining and C-banding analysis was carried out on 25 specimens of mole rats from 13 localities. The description of conventional karyotypes revealed the detailed pattern of geographic distribution of individual races of mole rats in Central Anatolia. The C-positive regions were localized in centromeric areas, and/or in short arms of submetacentric and subtelocentric autosomes. In the 2n =40 race, C-heterochromatin regions were found in whole short arms of four biarmed autosomal pairs whereas C-heterochromatin was localized in pericentromeric areas of biarmed and acrocentric autosomes in the karyotypes of the other races. Autosomal pairs heteromorphic possibly due to deletion/addition of heterochromatin and euchromatin material in short arms were recorded in some populations of both the 2n =58 and 60 chromosome races. The distribution of nucleolar organizer regions (NORs) was described for the first time in the 2n = 40 and 58 races. The NORs were localized in four pairs of biarmed autosomes in all the studied chromosomal races in distal heterochromatic and euchromatic areas of the short arms. The results demonstrate the considerable extent of variation in C-heterochromatin and NORs distribution in karyotypes of mole rats from Anatolia.

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Phenetic and ecological plasticity in Arvicola has caused a long-standing dispute over the number of species within the genus, which is currently thought to consist of two aquatic (sapidus, amphibius) and one fossorial species (scherman). We used mitochondrial cytochrome b (cytb) gene sequences to reconstruct phylogenetic relationships between the fossorial and the aquatic water voles from the various regions of their European and Asiatic range. These two types differed morphologically and exhibited allopatric ranges. Our study provided 50 new haplotypes, generating a total dataset of 70 different water vole cytb haplotypes. Phylogenetic reconstructions retrieved two major lineages that were in a sister position to A. sapidus: a fossorial Swiss lineage and a widespread cluster, which contained aquatic and fossorial water voles from Europe and western Siberia. The phylogeographic architecture in water voles is explained by Quaternary climatic dynamics. Our results show that A. scherman in its present scope is not a monophyletic taxon.