PDF(Pubmed)
Abstract：
The Amur tiger is currently confronted with challenges of anthropogenic development, leading to its population becoming fragmented into two geographically isolated groups: smaller and larger ones. Small and isolated populations frequently face a greater extinction risk, yet the small tiger population\'s genetic status and survival potential have not been assessed. Here, a total of 210 samples of suspected Amur tiger feces were collected from this small population, and the genetic background and population survival potentials were assessed by using 14 microsatellite loci. Our results demonstrated that the mean number of alleles in all loci was 3.7 and expected heterozygosity was 0.6, indicating a comparatively lower level of population genetic diversity compared to previously reported studies on other subspecies. The genetic estimates of effective population size (Ne) and the Ne/N ratio were merely 7.6 and 0.152, respectively, representing lower values in comparison to the Amur tiger population in Sikhote-Alin (the larger group). However, multiple methods have indicated the possibility of genetic divergence within our isolated population under study. Meanwhile, the maximum kinship recorded was 0.441, and the mean inbreeding coefficient stood at 0.0868, both of which are higher than those observed in other endangered species, such as the African lion and the grey wolf. Additionally, we have identified a significant risk of future extinction if the lethal equivalents were to reach 6.26, which is higher than that of other large carnivores. Further, our simulation results indicated that an increase in the number of breeding females would enhance the prospects of this population. In summary, our findings provide a critical theoretical basis for further bailout strategies concerning Amur tigers.
摘要：
阿穆尔虎目前面临着人为发展的挑战,导致其人口分散为两个地理上孤立的群体：更小和更大的群体。小而孤立的种群经常面临更大的灭绝风险，然而，小老虎种群的遗传状况和生存潜力还没有被评估。这里,从这个小群体中共收集了210份疑似阿穆尔虎粪便样本,并使用14个微卫星基因座评估了遗传背景和种群生存潜力。我们的结果表明，所有基因座的等位基因平均数为3.7，预期杂合性为0.6，表明与先前报道的其他亚种研究相比，种群遗传多样性水平相对较低。有效种群大小（Ne）和Ne/N比的遗传估计值分别仅为7.6和0.152，与Sikhote-Alin（较大的群体）的阿穆尔虎种群相比，代表较低的值。然而,多种方法表明，在我们研究的孤立人群中存在遗传差异的可能性。同时,记录的最大亲属关系为0.441，平均近交系数为0.0868，均高于其他濒危物种的亲属关系，比如非洲狮和灰狼。此外,我们已经确定，如果致死当量达到6.26，则未来灭绝的风险很大，这高于其他大型食肉动物。Further,我们的模拟结果表明，繁殖雌性数量的增加将增强该种群的前景。总之,我们的发现为有关阿穆尔虎的进一步救助策略提供了重要的理论基础。
