Environmental genomics approaches for the study of multiple stressors in freshwater ecosystems

研究淡水生态系统多种压力源的环境基因组学方法

• 批准号: RGPIN-2017-04331
• 负责人: Cristescu, Melania
• 金额: $ 3.5万
• 依托单位: McGill University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2020
• 资助国家: 加拿大
• 起止时间: 2020-01-01 至 2021-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=708946
• 关键词: Environmental; genomics; approaches; study; multiple

The anthropogenic pressures currently applied to aquatic habitats (increased metal loads, high concentrations of nutrients, increased acidity, accelerated introduction of invasive species) can generate extreme environmental conditions that can alter the supported communities and compromise the function of these ecosystems. Evaluating the impact of multiple stressors on aquatic ecosystems is particularly challenging due to the interactions amongst sources of stress and amongst the organisms themselves as well as the complex ecological and evolutionary dynamics that follow after stress. The long-term research objective of the proposed work is to advance new, integrative approaches for the study of multiple stressors in aquatic ecosystems. I propose to use a combination of experimental evolution (mutation accumulation and mesocosm experiments) and genomic approaches (transcriptomics, population genetics and metabarcoding) as well as Daphnia as a model organism to evaluate the responses of aquatic communities to environmental stressors. By using a long-term mutation accumulation experiment we plan to examine the global transcritional divergence patterns in mutation lines propagated under minimal selection and in isolates propagated under selection. This approach will allow us to provide insights into the evolutionary forces that shape gene expression. We will explore the extent to which environmental stressors (heavy metals) alter the mutation rate as well as the global transcriptional pattern. By using a large mesocosm experiment coupled with population genomics and metabarcoding approaches we will evaluate how genetic diversity and community composition changes during imposed environmental changes. We will explore the genetic changes at the population level that precede major changes to community composition. Moreover the mesocosm experiment will allow us to identify the genes important for adaptive responses to stressors. Jointly, these studies will provide unprecedented insights into the complex linkages between exposure to stressors and 1) the long-term effects on genome stability, 2) the global transcriptional pattern, 3) the changes in genetic diversity and community composition, 4) the capacity for rapid response, and ultimately 5) the long-term health of natural populations. This unique combination of experimental evolution and environmental genomics will allow our research group to investigate the ramifications of multiple stressors on the structural and functional attributes of aquatic ecosystems at a previously unattainable level of detail, control and replication. The proposed studies will also allow us to develop and test new ecological genomic approaches for the study of multiple stressors. The proposed projects provide an excellent opportunity for multidisciplinary and collaborative training at both graduate and undergraduate levels.

目前对水生栖息地施加的人为压力（增加的金属负荷、高浓度的营养物质、增加的酸度、加速引入入侵物种）可能会产生极端的环境条件，从而改变所支持的群落并损害这些生态系统的功能。由于压力源之间和生物体本身之间的相互作用以及压力后复杂的生态和进化动态，评估多种压力源对水生生态系统的影响尤其具有挑战性。拟议工作的长期研究目标是提出新的综合方法来研究水生生态系统中的多种压力源。 我建议结合使用实验进化（突变积累和中生态实验）和基因组方法（转录组学、群体遗传学和元条形码）以及水蚤作为模式生物来评估水生群落对环境压力的反应。通过使用长期突变积累实验，我们计划检查在最小选择下繁殖的突变系和在选择下繁殖的分离株的全局转录分歧模式。这种方法将使我们能够深入了解塑造基因表达的进化力量。我们将探讨环境压力源（重金属）在多大程度上改变突变率以及整体转录模式。通过使用大型中生态实验结合群体基因组学和元条形码方法，我们将评估遗传多样性和群落组成在强加的环境变化期间如何变化。我们将探讨群落组成发生重大变化之前人口水平的遗传变化。此外，中宇宙实验将使我们能够识别对应激源适应性反应重要的基因。总之，这些研究将为暴露于压力源和 1) 对基因组稳定性的长期影响，2) 全球转录模式，3) 遗传多样性和群落组成的变化，4) 能力之间的复杂联系提供前所未有的见解。快速反应，最终5）自然人群的长期健康。 这种实验进化和环境基因组学的独特结合将使我们的研究小组能够以以前无法达到的细节、控制和复制水平来研究多种压力因素对水生生态系统结构和功能属性的影响。拟议的研究还将使我们能够开发和测试用于研究多种压力源的新生态基因组方法。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绝佳的机会。