The role of mitochondria in mediating or moderating disturbances in oxidative metabolism

我的研究项目集中在研究新陈代谢，以更好地了解环境压力因素如何影响野生鱼类，重点关注线粒体过程。为了实现这一目标，我的工作遵循三个主要主题，沿着不同的生物组织水平分开；从1)线粒体过程之间的机制联系的体外开发到2)将全动物反应与线粒体功能联系起来的实验室实验以及3)对实验湖区（IISD-ELA）野生鱼类的检查。主题1将侧重于线粒体对过氧化氢水平的控制。线粒体通常被认为是活性氧（ROS）的主要来源，活性氧的过量产生会导致氧化应激。本主题将使用分离的线粒体作为主要研究系统，从具有代表性的恒温动物（啮齿动物）开始，然后扩展到具有代表性的变温动物，以评估我的实验室目前的线粒体模型作为ROS的调节剂是否具有广泛的系统发育和生理相关性。主题2将评估细胞氧化代谢与个体热应激反应差异之间的关系。这将结合将氧化应激与生长、线粒体效率和代谢率升高以及热挑战的有害影响联系起来的假设。这项研究将涉及Salvelinus属的鱼类（例如溪鳟鱼和湖鳟鱼），它们原产于氧气充足、寒冷的水域，可能特别容易受到气候变暖的负面影响。在热胁迫条件下，个体鱼的生长动态将被评估，以测试是否较大的个体对热胁迫的耐受性较低。代谢和生理性能也将被评估，并用于验证标记在主题3中的应用。主题3将测试监测野生鱼类代谢限制或紊乱的非致死手段。本主题将探讨当地生态系统和环境特征如何影响野生鱼类的代谢。湖鳟鱼居住在IISD-ELA的几个小湖泊中，这些湖泊没有相互连接，形成了孤立的种群。然而，整个ELA的湖泊环境变化很大，特别是由于温度和氧气供应的波动。使用主题1和主题2中开发的方法，本主题将整合来自整个动物的代谢数据，线粒体功能分析（在主题2中得到验证）和分子水平（氧化应激），以确定代谢破坏是否与野生鱼类生活史特征的这些改变相关。该计划将有助于培养至少10名从博士到本科水平的高素质人才。这些受训者将发展从生化分析到设计和实施实地生理实验的技能。

My research program is focused on investigating metabolism to better understand how environmental stressors can impact wild fish with a focus on mitochondrial processes. To achieve this aim, my work follows 3 main themes that separate along differing levels of biological organization; from 1) in vitro development of mechanistic linkages among mitochondrial processes to 2) laboratory experiments linking whole animal responses with mitochondrial function and 3) examination of wild fish from the Experimental Lakes Area (IISD-ELA). Theme 1 will focus on mitochondrial control of hydrogen peroxide levels. Mitochondria are often blamed as a primary source of reactive oxygen species (ROS), the overproduction of which can lead to oxidative stress. This theme will use isolated mitochondria as the primary study system starting with representative endotherms (rodents) and then expanding to include representative ectotherms to evaluate if my lab's current model of mitochondria as regulators of ROS may have broad phylogenetic and physiological relevance. Theme 2 will evaluate the relationship between cellular oxidative metabolism and individual variation in responses to thermal challenge. This will combine hypotheses linking oxidative stress with elevated growth, mitochondrial efficiency and metabolic rate and the detrimental impacts of heat challenge. The study will involve fish of the genus Salvelinus (for example brook and lake trout), which are native to well-oxygenated, cold waters and may be particularly prone to the negative impacts of warming. Under conditions of thermal challenge, growth dynamics of individual fish will be evaluated to test if larger individuals have a lower tolerance to heat challenge. Metabolic and physiological performance will be evaluated as well and used to validate markers for application in Theme 3.Theme 3 will test for non-lethal means of monitoring metabolic limitation or disruption in wild fishes. This theme will examine how local ecosystem and environmental features impact wild fish metabolism. Lake Trout populate several small lakes in the IISD-ELA that are not interconnected, creating isolated populations. However, the lake environments vary substantial across the ELA, particularly due to fluctuation in temperature and oxygen availability. Using the methodology developed form themes 1 and 2, this theme will integrate metabolic data from the whole animal, mitochondrial function assays (validated in Theme 2) and the molecular level (oxidative stress) to determine if metabolic disruption correlates with these alterations in life-history traits in wild fish. The proposed program would contribute to the training of at least 10 highly qualified personnel from the PhD to undergraduate level. These trainees will develop skills ranging from biochemical analysis to the design and implementation of field-based physiological experiments.