Applicability of mitochondrial DNA for the identification of Arvicolid species from faecal samples: a case study from the threatened Cabrera's vole

Arvicolid mitochondrial genomes evolve faster than in any other mammalian lineage. The genetic diversity exhibited by these rodents contrasts sharply with their phenotypic homogeneity. Furthermore, faecal droppings from Arvicolid rodents of similar body size are almost undistinguishable on the basis of pellet morphology and content. In this study, we advantaged from their high genetic diversity vs. phenotypic homogeneity to document the applicability of mtDNA extraction from vole droppings for latter identification of such via a rapid and efficient nested PCR-based technique using the threatened Microtus cabrerae as a model species. We sequenced the mitochondrial control region from 75 individuals belonging to 11 species of Arvicolinae from Spain, Portugal, Greece and Italy, and an additional 19 sequences from ten Microtus species from other countries were downloaded from Genbank. Based on these control region sequences, we successfully designed and applied a nested PCR for M. cabrerae-specific and arvicolid-generic mtDNA markers to differentiate Cabrera's vole faecal samples among other species of the Arvicolinae subfamily. Although this study used Cabrera's vole as a model species, similar techniques based on mtDNA sequences may find a broader applicability for noninvasive genetic conservation of vole species and their populations.