Waits L, Taberlet P, Swenson J E, Sandegren F, Franzén R
Department of Fish and Wildlife Resources, University of Idaho, Moscow, ID 83844-1136, USA.
Mol Ecol. 2000 Apr;9(4):421-31. doi: 10.1046/j.1365-294x.2000.00892.x.
In the 1930s, the Scandinavian brown bear was close to extinction due to vigorous extermination programmes in Norway and Sweden. Increased protection of the brown bear in Scandinavia has resulted in the recovery of four subpopulations, which currently contain close to 1000 individuals. Effective conservation and management of the Scandinavian brown bear requires knowledge of the current levels of genetic diversity and gene flow among the four subpopulations. Earlier studies of mitochondrial DNA (mtDNA) diversity revealed extremely low levels of genetic variation, and population structure that grouped the three northern subpopulations in one genetic clade and the southernmost subpopulation in a second highly divergent clade. In this study, we extended the analysis of genetic diversity and gene flow in the Scandinavian brown bear using data from 19 nuclear DNA microsatellite loci. Results from the nuclear loci were strikingly different than the mtDNA results. Genetic diversity levels in the four subpopulations were equivalent to diversity levels in nonbottlenecked populations from North America, and significantly higher than levels in other bottlenecked and isolated brown bear populations. Gene flow levels between subpopulations ranged from low to moderate and were correlated with geographical distance. The substantial difference in results obtained using mtDNA and nuclear DNA markers stresses the importance of collecting data from both types of genetic markers before interpreting data and making recommendations for the conservation and management of natural populations. Based on the results from the mtDNA and nuclear DNA data sets, we propose one evolutionarily significant unit and four management units for the brown bear in Scandinavia.
20世纪30年代，由于挪威和瑞典大力推行灭绝计划，斯堪的纳维亚棕熊濒临灭绝。斯堪的纳维亚对棕熊保护力度的加大使得四个亚种群数量得以恢复，目前约有1000只个体。要对斯堪的纳维亚棕熊进行有效的保护和管理，需要了解这四个亚种群目前的遗传多样性水平和基因流动情况。早期对线粒体DNA（mtDNA）多样性的研究显示，其遗传变异水平极低，种群结构呈现出将三个北部亚种群归为一个遗传分支，而最南端的亚种群则归为另一个高度分化的分支。在本研究中，我们利用来自19个核DNA微卫星位点的数据，对斯堪的纳维亚棕熊的遗传多样性和基因流动进行了更深入的分析。核基因座的结果与mtDNA的结果显著不同。四个亚种群的遗传多样性水平与北美未经历瓶颈效应的种群相当，且显著高于其他经历瓶颈效应和隔离的棕熊种群。亚种群之间的基因流动水平从低到中等，且与地理距离相关。使用mtDNA和核DNA标记获得的结果存在实质性差异，这凸显了在解释数据并为自然种群的保护和管理提出建议之前，同时收集这两种遗传标记数据的重要性。基于mtDNA和核DNA数据集的结果，我们为斯堪的纳维亚棕熊提出了一个具有进化意义的单元和四个管理单元。
