PDF(Pubmed)
Abstract：
Examining patterns of genetic diversity are crucial for conservation planning on endangered species, while inferring the underlying process of recent anthropogenic habitat modifications in the context potential long-term demographic changes remains challenging. The globally endangered scaly-sided merganser (SSME), Mergus squamatus, is endemic to a narrow range in Northeast Asia, and its population has recently been contracted into two main breeding areas. Although low genetic diversity has been suggested in the Russian population, the genetic status and demographic history of these individuals have not been fully elucidated. We therefore examined the genetic diversity and structure of the breeding populations of the SSME and investigated the relative importance of historical and recent demographic changes to the present-day pattern of genetic diversity. Using 10 nuclear microsatellite (SSR) markers and mitochondrial DNA (mtDNA) control region sequences, we found limited female-inherited genetic diversity and a high level of nuclear genetic diversity. In addition, analysis of both markers consistently revealed significant but weak divergence between the breeding populations. Inconsistent demographic history parameters calculated from mtDNA and bottleneck analysis results based on SSR suggested a stable historical effective population size. By applying approximate Bayesian computation, it was estimated that populations started to genetically diverge from each other due to recent fragmentation events caused by anthropogenic effects rather than isolation during Last Glacial Maximum (LGM) and post-LGM recolonization. These results suggest that limited historical population size and shallow evolutionary history may be potential factors contributing to the contemporary genetic diversity pattern of breeding SSME populations. Conservation efforts should focus on protecting the current breeding habitats from further destruction, with priority given to both the Russian and Chinese population, as well as restoring the connected suitable breeding grounds.
摘要：
研究遗传多样性的模式对于濒危物种的保护规划至关重要，尽管在潜在的长期人口变化的背景下推断最近人为栖息地改变的潜在过程仍然具有挑战性。全球濒临灭绝的鳞状白沙（SSME），羊百虫，是东北亚狭窄地区特有的，其种群最近被收缩到两个主要的繁殖区。尽管俄罗斯人口中存在低遗传多样性，这些个体的遗传状况和人口统计学史尚未完全阐明.因此，我们研究了SSME育种种群的遗传多样性和结构，并研究了历史和近期人口变化对当今遗传多样性模式的相对重要性。使用10个核微卫星（SSR）标记和线粒体DNA（mtDNA）控制区序列，我们发现了有限的女性遗传遗传多样性和高水平的核遗传多样性。此外,对这两个标记的分析一致显示，育种种群之间存在明显但弱的差异。根据mtDNA和基于SSR的瓶颈分析结果计算出的不一致的人口统计学历史参数表明，稳定的历史有效人口规模。通过应用近似贝叶斯计算，据估计,由于最近一次由人为效应引起的碎片化事件,而不是在最后一次冰川最大期(LGM)和LGM后重新定殖期间隔离,种群开始在基因上产生差异.这些结果表明，有限的历史种群规模和浅层的进化史可能是导致育种SSME种群当代遗传多样性模式的潜在因素。保护工作应侧重于保护当前的繁殖栖息地免受进一步破坏，优先考虑俄罗斯和中国人口，以及恢复连接的合适的繁殖地。
