The Impact of climate change on immunity in hypoxia-tolerant pacific reef fishes

环境缺氧对动物来说是致命的，许多鱼类暴露在海洋或潮间带池中的水生缺氧（即氧气有限）中。令人担忧的是，气候变化正在增加缺氧事件的频率和严重程度，以及水生环境中缺氧区域的规模。在过去的几十年里，全球变暖导致的水体温度升高与海洋中氧含量的减少有关，特别是在支持海洋水产养殖的沿海地区。因此，随着气候危机的加速，全球变暖导致的水生缺氧将会加剧，并对全球沿海海洋种群和水产养殖构成重大挑战。对所有动物来说，正常运作的免疫系统对生存至关重要，也是鱼类抵抗细菌和病毒感染以及从伤害中愈合和恢复的关键。缺氧和高温会损害免疫反应，因此，全球变暖和水生动物缺氧发生率的增加可能会使水生动物免疫功能受损。尽管水生缺氧对环境造成了挑战，但一些物种已经适应了有效的策略来确保它们在氧气有限的情况下生存。特别令人感兴趣的是生活在热带地区潮间带池中的鱼类，在那里它们暴露在间歇性的严重缺氧中，再加上高温。这些耐缺氧鱼类提供了一个很好的模型，用于研究有利于耐缺氧与免疫的适应之间的相互作用。我们的目的是确定1)缺氧是否会激活耐缺氧和不耐缺氧鱼类的免疫反应，2)免疫系统激活是否会影响耐缺氧鱼类对缺氧的适应性生理反应，3)缺氧是否会影响鱼类的免疫能力。

Environmental hypoxia can be lethal to animals and many fish are exposed to aquatic hypoxia (i.e., limited oxygen) in the ocean or in intertidal pools. Alarmingly, climate change is increasing the frequency and severity of hypoxic events and the size of hypoxic regions in aquatic environments. In the past few decades, increases in aquatic temperatures mediated by global warming correlate with decreasing oxygen content in oceans, and particularly in coastal regions that support marine aquaculture. Thus, aquatic hypoxia due to global warming is expected to worsen with the acceleration of the climate crises and poses a significant challenge to coastal marine populations and aquaculture globally. For all animals, a properly functioning immune system is a crucial for survival, and key to the ability of fish to resist infection by bacteria and viruses, and to heal and recover from injury. Immune responses are impaired by hypoxia and by high temperatures and thus aquatic animals may be immunocompromised by the progression of global warming and increasing incidence of aquatic hypoxia. Despite the environmental challenge posed by aquatic hypoxia, some species have adapted efficient strategies to ensure their survival when oxygen is limited. Of particular interest are fishes that inhabit intertidal pools in tropical regions wherein they are exposed to intermittent periods of severe hypoxia, in combination with high water temperatures. These hypoxia-tolerant fishes provide an excellent model in which to investigate interactions between adaptations that favour hypoxia-tolerance vs immunity.Our OBJECTIVES are to determine 1) whether hypoxia activates an immune response in hypoxia-tolerant and -intolerant fishes, 2) whether immune system activation compromises adaptive physiological responses to hypoxia in hypoxia-tolerant fish, and 3) whether hypoxia compromises immune competency in fish.