Departamento de Medicina Genómica y Toxicología Ambiental, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, México, D.F., CP 04510, Mexico.
Rev Environ Contam Toxicol. 2014;227:79-106. doi: 10.1007/978-3-319-01327-5_3.
Studying the genetic diversity of wild populations that are affected by pollution provides a basis for estimating the risks of environmental contamination to both wildlife, and indirectly to humans. Such research strives to produce both a better understanding of the underlying mechanisms by which genetic diversity is affected,and the long-term effects of the pollutants involved.In this review, we summarize key aspects of the field of genetic ecotoxicology that encompasses using genetic patterns to examine metal pollutants as environmental stressors of natural animal populations. We address genetic changes that result from xenobiotic exposure versus genetic alterations that result from natural ecological processes. We also describe the relationship between metal exposure and changes in the genetic diversity of chronically exposed populations, and how the affected populations respond to environmental stress. Further, we assess the genetic diversity of animal populations that were exposed to metals, focusing on the literature that has been published since the year 2000.Our review disclosed that the most common metals found in aquatic and terrestrial ecosystems were Cd, Zn, Cu and Pb; however, differences in the occurrence between aquatic (Cd=Zn>Cu>Pb>Hg) and terrestrial (Cu>Cd>Pb>Zn>Ni)environments were observed. Several molecular markers were used to assess genetic diversity in impacted populations, the order of the most common ones of which were SSR's > allozyme > RAPD's > mtDNA sequencing> other molecular markers.Genetic diversity was reduced for nearly all animal populations that were exposed to a single metal, or a mixture of metals in aquatic ecosystems (except in Hyalella azteca, Littorina littorea, Salmo trutta, and Gobio gobio); however, the pattern was less clear when terrestrial ecosystems were analyzed.We propose that future research in the topic area of this paper emphasizes seven key areas of activity that pertain to the methodological design of genetic ecotoxicological studies. Collectively, these points are designed to provide more accurate data and a deeper understanding of the relationship between alterations in genetic diversity of impacted populations and metal exposures. In particular, we believe that the exact nature of all tested chemical pollutants be clearly described, biomarkers be included, sentinel organisms be used, testing be performed at multiple experimental sites, reference populations be sampled in close geographical proximity to where pollution occurs, and genetic structure parameters and high-throughput technology be more actively employed. Furthermore, we propose a new class of biomarkers,termed "biomarkers of permanent effect," which may include measures of genetic variability in impacted populations.
研究受污染的野生种群的遗传多样性为评估环境污染对野生动物乃至人类的潜在风险提供了依据。此类研究旨在深入了解遗传多样性受影响的潜在机制，并研究污染物的长期影响。在本综述中，我们总结了遗传生态毒理学领域的一些关键方面，该领域涵盖了利用遗传模式来研究金属污染物作为自然动物种群环境胁迫因子的情况。我们探讨了由于外来化合物暴露导致的遗传变化与自然生态过程导致的遗传改变。我们还描述了金属暴露与慢性暴露种群遗传多样性变化之间的关系，以及受影响种群对环境胁迫的响应。此外，我们评估了接触金属的动物种群的遗传多样性，重点关注了 2000 年以来发表的文献。我们的综述表明，水生和陆地生态系统中最常见的金属是 Cd、Zn、Cu 和 Pb；然而，水生环境（Cd=Zn>Cu>Pb>Hg）和陆地环境（Cu>Cd>Pb>Zn>Ni）中金属的发生情况存在差异。人们使用了多种分子标记来评估受影响种群的遗传多样性，其中最常见的标记依次为 SSR's > allozyme > RAPD's > mtDNA 测序>其他分子标记。几乎所有暴露于单一金属或金属混合物的水生生态系统中的动物种群的遗传多样性都降低了（除了 Hyalella azteca、Littorina littorea、Salmo trutta 和 Gobio gobio 之外）；然而，当分析陆地生态系统时，情况就不那么明显了。我们建议，未来在本文主题领域的研究应强调七个关键活动领域，这些领域涉及遗传生态毒理学研究的方法学设计。总的来说，这些要点旨在提供更准确的数据，并深入了解受影响种群遗传多样性变化与金属暴露之间的关系。特别是，我们认为应明确描述所有测试化学污染物的性质，纳入生物标志物，使用哨兵生物，在多个实验点进行测试，在污染发生地附近的地理相近区域采集参考种群样本，并更积极地使用遗传结构参数和高通量技术。此外，我们提出了一类新的生物标志物，称为“永久性效应生物标志物”，它可能包括受影响种群遗传变异性的度量。
