Sessions

The status of brown bear populations in Europe varies considerably across regions: while some populations are threatened, others are showing increasing trends. As apex predators, brown bears can pose a risk to humans and livestock, creating a complex management situation in which both conservation measures and regulated culling may be employed. Genetic individual identification can play an important role in population monitoring and wildlife forensic investigations, including cases of poaching or human-bear conflicts. It enables the identification of individuals from biological samples and support assessment of population status without relying exclusively on direct observations. Microsatellite markers are widely used for this purpose, and cost-effective modifications to established methods could facilitate their implementation across a broader range of laboratories.

The aim of this study was to investigate whether the UrsaPlex panel, originally developed for American black bears (Ursus americanus), could be applied in the Slovakian brown bear (Ursus arctos arctos) population, and adapted to a universal fluorescence labelling system. DNA was successfully extracted from 26 blood and tissue samples collected from Slovakian brown bears. In total ten microsatellite loci and three sex markers were amplified using fluorescently labelled universal primers and a modified PCR protocol. Genotyping was subsequently carried out using capillary electrophoresis.

Complete genotypes were obtained for all 26 samples. All ten microsatellite loci were polymorphic, with the number of observed alleles ranging from 2 to 9, and the number of effective alleles ranging from 1.2 to 5.6. Mean expected heterozygosity was 0.57, with locus-specific values measured between 0.14 and 0.82, while the observed heterozygosity averaged 0.55, with values calculated between 0.15 and 0.81. For the complete ten-locus panel, the combined probability of identity was 1.1 × 10⁻⁷, which means that the probability of two unrelated individuals having the same ten-locus genotype is approximately one in 9 million.

The results showed that the selected UrsaPlex markers can be successfully amplified in Slovakian brown bears without apparent limitations arising from the use of fluorescently labelled universal primers instead of conventional 5′-end-labelled forward primers. The ten-locus panel exhibited high discriminatory power for individual identification within the studied samples. Universal fluorescence labelling reduces the need for individually labelled locus-specific primers and thus offers a cost-effective approach to assay development. However, before routine application in population monitoring or wildlife forensic investigations, further assessment is required using larger sample sets and non-invasively collected samples.