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Murmansk, Russia

Kopatz A.,Norwegian Institute for Agricultural And Environmental Research Bioforsk | Kopatz A.,University of Oulu | Eiken H.G.,Norwegian Institute for Agricultural And Environmental Research Bioforsk | Hagen S.B.,Norwegian Institute for Agricultural And Environmental Research Bioforsk | And 14 more authors.
Conservation Genetics | Year: 2012

Loss of connectivity and habitat destruction may lead to genetic depletion of wild animal populations, especially in species requiring large, connected territories as the brown bear (Ursus arctos). Brown bear populations of North Western Russia, Finland and Northern Norway have been assumed to form one large, continuous population; however this hypothesis has not been tested sufficiently. We have genotyped 1,887 samples from 2005 to 2008 from four distinct areas and used the resulting DNA profiles from 146 different individuals to analyze the genetic diversity, population structure, and the migration rates among groups. In addition, we have tested for traces of previous genetic bottlenecks. Individuals from Eastern Finland and Russian Karelia were grouped in the same cluster ("Karelia"), while distinctive subpopulations of brown bears were detected in the north ("Pasvik"), and the east ("Pinega"). All three subpopulations displayed high genetic variation, with expected heterozygosities (HE) of 0. 77-0. 81, but differentiation among the clusters was relatively low (average FST = 0. 051, P < 0. 001). No evidence of genetic bottlenecks in the past was found. We detected a highly significant isolation-by-distance (IBD) pattern. For Pasvik, self-recruitment was found to be very high (96%), pointing to the possibility of genetic isolation. In contrast, between Karelia and Pinega we detected high, bi-directional migration rates (~30%), indicating genetic exchange. Conclusively, despite of a substantial influence of IBD on the genetic structure in the region, we detected considerable variation in connectivity among the identified clusters that could not be explained solely by the distance between them. © 2012 Springer Science+Business Media B.V. Source

Schregel J.,Norwegian Institute for Agricultural And Environmental Research Bioforsk | Schregel J.,University of Life science | Kopatz A.,Norwegian Institute for Agricultural And Environmental Research Bioforsk | Kopatz A.,University of Oulu | And 18 more authors.
Molecular Ecology | Year: 2012

Noninvasively collected genetic data can be used to analyse large-scale connectivity patterns among populations of large predators without disturbing them, which may contribute to unravel the species' roles in natural ecosystems and their requirements for long-term survival. The demographic history of brown bears (Ursus arctos) in Northern Europe indicates several extinction and recolonization events, but little is known about present gene flow between populations of the east and west. We used 12 validated microsatellite markers to analyse 1580 hair and faecal samples collected during six consecutive years (2005-2010) in the Pasvik Valley at 70°N on the border of Norway, Finland and Russia. Our results showed an overall high correlation between the annual estimates of population size (N c), density (D), effective size (N e) and N e/N c ratio. Furthermore, we observed a genetic heterogeneity of ∼0.8 and high N e/N c ratios of ∼0.6, which suggests gene flow from the east. Thus, we expanded the population genetic study to include Karelia (Russia, Finland), Västerbotten (Sweden) and Troms (Norway) (477 individuals in total) and detected four distinct genetic clusters with low migration rates among the regions. More specifically, we found that differentiation was relatively low from the Pasvik Valley towards the south and east, whereas, in contrast, moderately high pairwise F ST values (0.91-0.12) were detected between the east and the west. Our results indicate ongoing limits to gene flow towards the west, and the existence of barriers to migration between eastern and western brown bear populations in Northern Europe. © 2012 Blackwell Publishing Ltd. Source

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