Current status of genetic diversity and population structure in the endangered Asiatic Black Bear population restoring in South Korea

Since the endangered Asiatic black bear restoration project began in South Korea, the wild population has recently been over 100 bears. This study examined the genetic diversity and population structure of the current bear population using microsatellite genotypes. Mean observed and expected heterozygosities and polymorphic information content were 0.691±0.108, 0.712±0.046 and 0.663±0.272 in the entire population, respectively, demonstrating that this bear population maintained a relatively high level of genetic diversity. The population structure analysis results indicate that ΔK was the highest (11.65) when K was set at 5, suggesting that the population originated from at least five genetic clusters. The principal component analysis (PCA) results showed that bears reintroduced from Northeast Asia are not distinguished by region-specific genetic clusters, estimating that they has been evolved from a single common origin. The progeny population showed the decreased genetic diversity compared to the founder population, which is estimated to be a result of inbreeding and reproductive dominance by a small number of superior bears. When offspring produced through captive breeding were supplied to the wild, genetic diversity was shown to increase. The results of this study suggest that in order to improve the genetic diversity and ensure the genetic stability of this Asiatic black bear population, it is necessary to manage some dominant breeding superiors in the wild, supply offspring through human-assisted reproduction such as artificial insemination, reintroduce new bears from overseas. This study will provide critical information for establishing management programs and policy for future direction of co-existence with the endangered Asiatic black bears in South Korea beyond restoration.