Environmental, hormonal and cellular correlates of thermal biology and adaptation in fish.

这项NSERC发现研究计划将调查甲状腺激素和应激蛋白（热休克蛋白，HSPs）的功能，以了解鱼类如何应对不断变化的环境和极端环境（温度）。不管原因是什么（人为还是自然），世界气候在过去50-100年间一直在变化，而且变化更大。淡水鱼是变温动物（不能使用内部过程来调节体温），它们在身体上逃离不适宜的温度的能力有限，因此它们可能对气候变化的影响特别敏感。该项目将研究湖白鱼，这是一种冷水，热敏鱼，生长在2-4°C，生活在深水湖泊，全年深水温度为10-13°C。作为北美商业捕捞最多的淡水鱼，白鱼对我们原住民来说非常重要，在经济和文化上都非常有价值。这一事实，再加上它们对温暖温度的敏感性以及在实验室中易于处理和饲养，使湖白鱼成为研究适应热应激和不断变化的环境的理想物种。甲状腺激素是所有脊椎动物（有脊椎的动物）的关键代谢激素，是哺乳动物和其他恒温动物调节体温的基础。尽管如此，甲状腺激素在调节代谢中的作用，因为它与热生物学和应激有关，在鱼类和其他变温动物中仍有待研究。本研究项目旨在了解甲状腺激素在热应激和适应温度变化中的功能，以及所涉及的精确的细胞和生理（内部）机制。在不同的热环境下，甲状腺激素在线粒体生物能量学和生物合成中的作用将被研究。这些研究将有助于更好地理解变温动物的热生物学，并可能为了解甲状腺激素在恒温动物中的作用的演变提供见解。这项研究的一个关键方面是我能够研究萨斯喀彻温省湖泊白鱼的野生种群，它们生活在非常浅的湖泊中，夏季通常会达到湖泊白鱼的致命温度极限（23-25°C）。这些湖白鱼种群已经适应了生活在该物种通常存在的温度限制之外。通过使用蛋白质组学方法对萨斯喀彻温省浅湖鱼类和深湖鱼类之间的总蛋白质谱进行直接比较，我的研究小组将确定细胞水平上参与热适应的关键系统。在这个NSERC发现项目的过程中，我和我的研究团队（3名研究生和8名本科生）将在我们对鱼类如何适应不断变化的环境的理解方面取得重大进展。最终，这项工作将提供一些必要的信息，帮助我们了解热敏鱼类如何适应和生存不断变化的气候。

This NSERC discovery research program will investigate the function of thyroid hormones and stress proteins (heat shock proteins, HSPs) to understand how fish respond to changing environments and environmental (temperature) extremes. Irrespective of the cause (human versus natural), the world’s climate has been changing over the past 50-100 years and has been more variable. Freshwater fish are ectotherms (unable to use internal processes to regulate body temperature) and restricted in their ability to physically escape inhospitable temperatures, thus they may be particularly sensitive to the effects of climate changes. This program will study lake whitefish, a cold water, thermally sensitive fish that develops at 2-4°C and lives in deep lakes with year round deep water temperatures of 10-13°C. As the most commercially fished, freshwater fish in North America and a fish of great importance to our First Nations People, whitefish are very valuable both economically and culturally. This fact, coupled with their sensitivity to warm temperatures and ease of handling and rearing in the laboratory, make lake whitefish an ideal species to study adaptation to thermal stress and changing environments. Thyroid hormones are key metabolic hormones in all vertebrates (animals with a backbone) and are fundamental in regulating body temperature in mammals and other endotherms. Despite this fact, the role of thyroid hormones in regulating metabolism as it relates to thermal biology and stress remains to be investigated in fish and other ectotherms. This research program specifically seeks to understand the function of thyroid hormones in thermal stress and adaptation to changing temperatures and the precise cellular and physiological (internal) mechanisms involved. The function of thyroid hormones in mitochondrial bioenergetics and biosynthesis under different thermal regimes will be investigated. These studies will lead to a better understanding of thermal biology in ectotherms and may offer insight into the evolution of the role of thyroid hormones in endothermy. One key aspect of this research is my ability to study wild populations of lake whitefish in Saskatchewan that are living in very shallow lakes which in the summer months routinely reach the lethal temperature limit (23-25°C) for lake whitefish. These populations of lake whitefish have adapted to living outside the temperature limits in which the species is normally found. By using a proteomic approach to make a direct comparison of the total protein profiles between fish in shallow lakes and those living in deep lakes in Saskatchewan, my research team will identify the key systems involved in thermal adaption at the cellular level. Over the course of this NSERC discovery program my research team (3 graduate and 8 undergraduate students) and I will make significant advances in our understanding of how fish adapt to changing environments. Ultimately, this work will provide some of the necessary information to help us understand how thermally sensitive fish may adapt and survive a changing climate.