Gansu Key Laboratory of Biomonitoring and Bioremediation for Environmental Pollution, School of Life Sciences, Lanzhou University, Lanzhou, 730000, China.
Key Laboratory of Zoological Systematics and Evolution, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China.
Environ Pollut. 2020 Aug;263(Pt B):114396. doi: 10.1016/j.envpol.2020.114396. Epub 2020 Mar 19.
Genetic diversity is the bedrock of evolution. The "Genetic Erosion" hypothesis posits that environmental pollution could cause reduced genetic diversity. To explore the effects of heavy metal pollution on genetic diversity in natural populations, we selected an area with more than sixty years of heavy metal contamination (Baiyin, BY) and a relatively unpolluted one (Liujiaxia, LJX), and tree sparrow (Passer montanus) as study models. Five tree sparrow populations were sampled in BY at sites differing in heavy metal pollution level. Lower genetic diversity based on seven microsatellite loci was observed in the five tree sparrow populations from BY compared with those from LJX. Analysis of molecular variance indicated no significant genetic differentiation between BY and LJX. However, the observed heterozygosity and allelic richness were negatively correlated to the lead and cadmium concentrations in the primary feathers of tree sparrow. Our results indicated the genetic diversity might have a negative response to long-term environmental heavy metal pollution in tree sparrow, supporting the "Genetic Erosion" hypothesis. Therefore, the findings shed lights on the possible effects of heavy metal pollution on genetic diversity of wild bird populations.
遗传多样性是进化的基石。“遗传侵蚀”假说认为，环境污染可能导致遗传多样性降低。为了探究重金属污染对自然种群遗传多样性的影响，我们选择了一个有六十多年重金属污染历史的地区（白银，BY）和一个相对未受污染的地区（刘家峡，LJX），并以树麻雀（Passer montanus）为研究模型。在 BY 地区，我们在不同重金属污染水平的地点采集了五个树麻雀种群。与 LJX 地区的种群相比，来自 BY 的五个树麻雀种群的七个微卫星位点的遗传多样性较低。基于分子方差分析的结果表明，BY 和 LJX 之间没有明显的遗传分化。然而，观察到的杂合度和等位基因丰富度与树麻雀初级飞羽中的铅和镉浓度呈负相关。我们的结果表明，遗传多样性可能对树麻雀长期的环境重金属污染产生负面响应，支持“遗传侵蚀”假说。因此，这些发现揭示了重金属污染对野生鸟类种群遗传多样性的可能影响。
