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The bicolored shrew Crocidura leucodon consists of two phylogeographic lineages which diverged during the Middle Pleistocene and are roughly separated by the Bosporus Strait at the contact point of Europe and Asia Minor. In this study we analysed mitochondrial cytochrome b genes (1137 bp) of nine shrews from the Caspian region in Iran. Phylogenetic trees obtained in Maximum Likelihood and Bayesian analyses retrieved a sister position of our Iranian haplotypes (Iranian lineage) against all the remaining C. leucodon samples from Europe, Turkey and Georgia (Euro-Asian lineage). Identical topology was also evident from the unrooted phylogenetic network. The Euro-Asian and the Iranian lineages were separated by a K2P genetic distance of 7.5 ± 0.9 and diverged 1.14 Mya (95% CI: 0.841–1.616). The geographic range of the Iranian lineage is evidently restricted to the Hyrcanian region south of the Caspian Sea which abounds with small range mammalian endemics. [ABSTRACT FROM AUTHOR]

Background: The phylogeography of the house mouse (Mus musculus L.), an emblematic species for genetic and biomedical studies, is only partly understood, essentially because of a sampling bias towards its most peripheral populations in Europe, Asia and the Americas. Moreover, the present-day phylogeographic hypotheses stem mostly from the study of mitochondrial lineages. In this article, we complement the mtDNA studies with a comprehensive survey of nuclear markers (19 microsatellite loci) typed in 963 individuals from 47 population samples, with an emphasis on the putative Middle-Eastern centre of dispersal of the species. Results: Based on correspondence analysis, distance and allele-sharing trees, we find a good coherence between geographical origin and genetic make-up of the populations. We thus confirm the clear distinction of the three best described peripheral subspecies, M. m. musculus, M. m. domesticus and M. m. castaneus. A large diversity was found in the Iranian populations, which have had an unclear taxonomic status to date. In addition to samples with clear affiliation to M. m. musculus and M. m. domesticus, we find two genetic groups in Central and South East Iran, which are as distinct from each other as they are from the south-east Asian M. m. castaneus. These groups were previously also found to harbor distinct mitochondrial haplotypes. Conclusion: We propose that the Iranian plateau is home to two more taxonomic units displaying complex primary and secondary relationships with their long recognized neighbours. This central region emerges as the area with the highest known diversity of mouse lineages within a restricted geographical area, designating it as the focal place to study the mechanisms of speciation and diversification of this species. [ABSTRACT FROM AUTHOR]