Environmental Stressors and the Mutation Process

在加拿大，来自人为和自然来源的金属污染仍然严重威胁着水生环境的健康以及依赖它们的人民和经济。许多加拿大地盾湖经历多种人为压力，如酸化，钙耗竭，入侵物种，以及有机和无机污染物的稳步增加。在众多的自然和人为压力因素中，金属污染特别令人关注。此外，加拿大北方地区采矿活动的增加迫切需要了解金属污染如何影响淡水生态系统的长期可持续性，并在其他环境压力因素（如钙下降）的背景下研究金属污染。拟议的研究将调查低浓度、非致死浓度的金属（例如，Ni，Cu，Ni + Cu），金属诱导突变的适应性，以及利用生态学、进化学、基因组学、毒理学观点和蚤状蚤（Daphnia pulex）作为模式物种的方法，群体进化金属耐受性的能力。这些研究将为低慢性金属暴露及其对基因组稳定性和自然人群长期健康的影响之间的复杂联系提供前所未有的见解。跨学科的方法也将使自然种群中进化的金属耐受性的遗传基础的调查。长期的突变积累实验，加上群体遗传学和污染和未污染的栖息地的实地研究，将提供新的资源，了解在人口水平上的金属诱导的突变过程。拟议的项目提供了一个很好的机会，在研究生和本科层次的多学科和协作培训。

In Canada, metal contamination from both anthropogenic and natural sources remains a serious threat to the health of both aquatic environments, and the people and economies relying on them. Many of the Canadian Shield lakes experience multiple anthropogenic stressors such as acidification, calcium depletion, invasive species, and a steady increase in both organic and inorganic contaminants. Among the multitude of natural and anthropogenic stressors, metal pollution is of particular concern. Moreover, the increased mining activities in the northern parts of Canada generate a pressing need to understand how metal pollution affects the long term sustainability of freshwater ecosystems and to study metal contamination in the context of other environmental stressors such as calcium decline. The proposed research will investigate the long-term mutagenic consequences of low, non-lethal concentrations of metals (e.g., Ni, Cu, Ni + Cu), the fitness properties of metal-induced mutations, and the ability of populations to evolve metal tolerance using approaches that integrate ecological, evolutionary, genomic, toxicological perspectives and Daphnia pulex as a model species. These studies will provide unprecedented insights into the complex linkages between low chronic metal exposure and its effects on genome stability and the long term health of natural populations. The interdisciplinary approaches will also enable the investigation of the genetic basis of evolved metal tolerance in natural populations. The long-term mutation accumulation experiments coupled with population genetics and field studies on contaminated and uncontaminated habitats will provide novel resources for understanding the metal-induced mutation process at the population level. The proposed projects provide an excellent opportunity for multidisciplinary and collaborative training at both graduate and undergraduate levels.