Environmental Stressors and the Mutation Process

在加拿大，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，以及依赖这些环境的人民和经济。许多加拿大屏蔽湖经历了多种人为压力，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应激源中，金属污染尤其令人担忧。此外，加拿大北部采矿活动增加，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，并在钙含量下降等其他环境压力因素的背景下研究金属污染。这项拟议的研究将调查低浓度、非致命性金属(如镍、铜、镍+铜)的长期诱变后果，金属诱导突变的适宜性，以及种群利用整合生态、进化、基因组和毒理学观点的方法进化金属耐受性的能力，并将脉冲水蚤作为模式物种。这些研究将对低长期金属暴露及其对基因组稳定性和自然人口长期健康的影响之间的复杂联系提供前所未有的见解。这种跨学科的方法还将使研究自然种群中进化的金属耐受性的遗传基础成为可能。长期的突变积累实验与种群遗传学和对污染和未污染生境的实地研究相结合，将为在种群水平上理解金属诱导的突变过程提供新的资源。拟议的项目为研究生和本科生的多学科和协作培训提供了极好的机会。

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.