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

我的研究计划专注于研究新陈代谢，以更好地了解环境应激源如何影响野生鱼类，重点是线粒体过程。为了实现这一目标，我的工作遵循三个主题，它们沿着不同的生物组织水平分开；从1)线粒体过程之间的机械联系的体外发展到2)将整个动物的反应与线粒体功能联系起来的实验室实验以及3)实验湖区野生鱼类的检查(IISD-ELA)。 主题1将集中于线粒体对过氧化氢水平的控制。线粒体经常被认为是活性氧物种(ROS)的主要来源，ROS的过度产生可能导致氧化应激。本主题将使用分离的线粒体作为主要的研究系统，从典型的吸热动物(啮齿动物)开始，然后扩展到包括典型的外温动物，以评估我的实验室目前作为ROS调节器的线粒体模型是否具有广泛的系统发生和生理相关性。 主题2将评估细胞氧化代谢与个体对热挑战反应的差异之间的关系。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(例如小溪和湖泊鲑鱼)，这种鱼原产于氧气充足的寒冷水域，可能特别容易受到气候变暖的负面影响。在热挑战条件下，将评估个体的生长动态，以测试较大的个体是否对热挑战的耐受性较低。代谢和生理表现也将被评估，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新陈代谢限制或干扰的非致命性手段。本主题将研究当地生态系统和环境特征如何影响野生鱼类的新陈代谢。鲑鱼湖分布在IISD-ELA的几个没有相互联系的小湖泊中，造成了孤立的种群。然而，整个ELA的湖泊环境差异很大，特别是由于温度和氧气可获得性的波动。利用主题1和主题2开发的方法，该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)，以确定代谢中断是否与野生鱼类生活史特征的这些变化有关。 拟议的计划将有助于培训至少10名从博士到本科生的高素质人员。这些受训人员将发展从生化分析到设计和实施现场生理实验的各种技能。

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.