Mechanisms and Evolution of Hypoxia Tolerance

耐缺氧的机制和进化

• 批准号: RGPIN-2015-05337
• 负责人: Richards, Jeffrey
• 金额: $ 4.15万
• 依托单位: University of British Columbia
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2016
• 资助国家: 加拿大
• 起止时间: 2016-01-01 至 2017-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=613494
• 关键词: Mechanisms; Evolution; Hypoxia; Tolerance

For most air-breathing vertebrates, decreases in environmental oxygen (termed hypoxia) are a rare occurrence, but when they do occur they can have devastating metabolic consequences resulting in death within minutes. In the aquatic environment however, periods of hypoxia are a common, naturally occurring phenomenon. In light of this, it is perhaps not surprising that among all vertebrates, fish boast the largest number of hypoxia tolerant species. Hypoxia has clearly played an important role in shaping the evolution of traits that enhance their survival during hypoxia exposure. Despite several decades of study, we still do not have a complete understanding of the factors that explain why there is variation in hypoxia tolerance among fish and the biochemical mechanisms that explain why some fish are more tolerant of hypoxia than others. To address this knowledge gap, my research program uses the natural variation in hypoxia tolerance seen among a group of closely related fish species called sculpins, which inhabit the marine near shore environment, from tidepools to deep waters. Some species live only within tidepools, which are environments that are heavily influenced by the daily tidal cycle, resulting in large, daily fluctuations in oxygen, temperature, salinity, pH, etc, while other species are confined to subtidal environments and deeper waters that do not experience fluctuations in these parameters. My research program uses these sculpins along with a combination of common garden experiments and hypoxia exposures, in adults, parents, and developing embryos, to determine whether variation in hypoxia tolerance is due to genetically based natural selection and adaptation or due to previous hypoxia exposure during the organism’s lifetime. In addition, we investigate the molecular, biochemical, and physiological mechanisms that explain variation in hypoxia tolerance in these sculpins. Research of this nature is important because the prevalence of aquatic hypoxia is on the rise due to human-related activities, thus fishes and other aquatic organisms are now experiencing unprecedented fluctuations in their environment that are testing their tolerance limits. Understanding the factors that set species’ tolerance limits to hypoxia is an essential first step in predicting which animals will be most at risk due to a changing environment. This grant will allow me to train 5 graduate (3PhD & 2MSc) and 2 undergraduate (1 BSc Honors & 1 NSERC-USRA) students per year in the most advanced analytical and conceptual approaches for understanding how animals interact with their environment.

对于大多数空气呼吸脊椎动物，环境氧（称为缺氧）的减少是罕见的，但是当它们发生时，它们可能会在几分钟内带来毁灭性的代谢后果。但是，在水生环境中，缺氧的时期是一种常见的，天然存在的现象。鉴于这种情况，在所有脊椎动物中，Fish拥有最多的低氧耐受物种，这不足为奇。缺氧显然在塑造特征的演变中发挥了重要作用，从而增强其在缺氧期间的存活率。尽管进行了数十年的研究，但我们仍然没有完全了解鱼类中缺氧耐受性和生化机制的因素，这些因素解释了为什么某些鱼比其他鱼更容易耐受性。为了解决这一知识差距，我的研究计划使用了缺氧耐受性的自然变化，请参见一组称为sculpins的紧密相关的鱼类物种，这些鱼类会影响从潮汐池到深水的海岸环境附近的海洋。一些物种仅生活在潮汐池中，这些环境受到日常潮汐周期影响的环境，导致氧，温度，温度，盐度，pH等的每日大量波动，而其他物种则局限于潮汐环境和较深的水域，这些水中没有这些参数中波动。我的研究计划使用这些雕塑蛋白以及成人，父母和发展胚胎的常见花园实验和缺氧暴露的结合，以确定低氧耐受性的变化是由于基于遗传的自然选择和适应性而引起的，或者是由于生物体生命中先前的低氧暴露。此外，我们研究了解释这些雕塑蛋白中缺氧耐受性变化的分子，生化和物理机制。对这种性质的研究很重要，因为由于与人相关的活动，水生缺氧的普遍性正在上升，因此鱼类和其他水生生物现在正在其环境中经历前所未有的波动，这些波动正在测试其耐受性限制。了解设定物种对缺氧的容忍度限制的因素是预测哪些动物由于环境变化而处于最大风险的第一步。这笔赠款将使我能够以最先进的分析和概念性方法来培训5名毕业生（3PHD和2MSC）和2名本科生（1 BSC荣誉和1名NSERC-ISRA）学生，以了解动物如何与环境互动。