Environmental Stressors and the Mutation Process

在加拿大，人为和自然来源的金属污染仍然对水生环境的健康以及依赖水生环境的人民和经济构成严重威胁。许多加拿大盾湖经历着多种人为压力因素，如酸化、钙耗尽、入侵物种以及有机和无机污染物的稳步增加。在众多自然和人为的压力源中，金属污染尤其令人担忧。此外，加拿大北部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。该研究将研究低、非致死浓度金属（如Ni、Cu、Ni + Cu）的长期诱变后果，金属诱导突变的适应度特性，以及群体进化金属耐受性的能力，采用综合生态学、进化学、基因组学、毒理学观点和水蚤作为模式物种的方法。这些研究将为低剂量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。跨学科的方法也将能够调查自然种群中进化的金属耐受性的遗传基础。长期的突变积累实验、种群遗传学和污染与未污染生境的野外研究将为在种群水平上理解金属诱导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.