Mechanisms and evolution of hypoxia tolerance

环境缺氧是许多水生生态系统中常见的自然现象。鉴于此，在所有脊椎动物中，鱼类拥有最多的耐缺氧物种也许并不奇怪。缺氧显然在塑造特征的进化中发挥了重要作用，以提高缺氧存活率。然而，尽管经过了几十年的研究，我们仍然没有完全了解解释缺氧耐受性变化的因素。为了解决这一知识差距，我的研究项目利用鱼类群体之间缺氧耐受性的自然变化来确定缺氧耐受性背后的重要分子、细胞和生化机制。此外，我们在成人和发育中的胚胎中使用了普通花园实验和缺氧暴露的组合，以梳理鱼类之间缺氧耐受性的变化是由于自然选择和适应还是由于生物体一生中先前的缺氧暴露。这种性质的研究很重要，因为由于与人类有关的活动，水生缺氧的发生率正在上升，因此，鱼类和其他水生生物现在正经历着前所未有的环境波动，这些波动正在考验它们的容忍极限。了解设定物种对缺氧的耐受极限的因素是预测哪些动物由于环境变化而面临最大风险的重要的第一步。此外，了解动物缺氧的基本生物学，这些动物已经进化出生存机制，无疑将为生物医学研究的候选系统提供线索。这笔资助将允许我培养至少4名博士，5名硕士和12名学士，用最先进的分析和概念方法来理解动物如何与环境相互作用。

Environmental hypoxia is a common, naturally occurring phenomenon in many aquatic ecosystems. 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 to enhance hypoxia survival. Despite several decades of study however, we still do not have a complete understanding of the factors that explain variation in hypoxia tolerance. To address this knowledge gap, my research program uses the natural variation in hypoxia tolerance seen among groups of fish to determine the important molecular, cellular, and biochemical mechanisms that underlie hypoxia tolerance. In addition, we use a combination of common garden experiments and hypoxia exposures, in adults and developing embryos, to tease out whether variation in hypoxia tolerance among fish species is due to natural selection and adaptation or due to previous hypoxia exposure during the organism's lifetime. Research of this nature is important because the prevalence of aquatic hypoxia is on the rise due to human-related activities, and as such, fishes and other aquatic organisms are now experiencing unprecedented fluctuations in their environment that are testing their tolerance limits. Understanding the factors that set a species' tolerance limits to hypoxia is an essential first step in predicting which animals are most a risk due to a changing environment. Furthermore, understanding the basic biology of hypoxia in animals that have evolved mechanism to survive it will undoubtedly shed light on candidate systems for biomedical research. This grant will allow me to train at least 4 Ph.D., 5 M.Sc., and 12 B.Sc. students in the most advanced analytical and conceptual approaches for understanding how animals interact with their environment.