Genetic variability among root voles (Microtus oeconomus) from different geographic regions: populations can be distinguished by DNA fingerprinting

Genetic variability among root voles (Microtus oeconomus Pallas, 1776]) originating from two distantly separate regions of Norway (Valdres and Finnmark) was studied by DNA fingerprinting using the probes 33.15, 33.6 and M13. All three probes revealed polymorphic, although relatively simple, patterns. DNA fingerprint banding patterns were clearly diagnostic of the animals' region of origin. Notably, Valdres animals display a high molecular-weight cluster of bands not found in Finnmark, reflective of the isolation, and possibly an indication of separate colonization events, of the two groups. On the local level in Finnmark, bands associating with a specific trap site were observed in trappings on consecutive years. Comparisons of Finnmark animals taken at three trap sites at approximately 10 km intervals show a gradient of genetic similarity. Captive bred siblings were also compared, yielding average values significantly higher than those seen from same-site comparisons. We suggest that the sensitivity provided by DNA fingerprinting with multi-locus minisatellite probes is appropriate for population genetic studies in M. oeconomus. Also, because band-sharing correlates to spacing in M. oeconomus, we propose that DNA fingerprinting may be used to study dispersal, recruitment and other population processes in this and possibly other rodent species.