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

环境缺氧对动物可能是致命的，许多鱼暴露在海洋或潮间带池塘中的水生缺氧(即有限的氧气)中。令人担忧的是，气候变化正在增加低氧事件的频率和严重程度，以及水环境中低氧区域的大小。在过去的几十年里，全球变暖导致的水温升高与海洋含氧量的下降相关，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，全球变暖造成的水生缺氧预计将恶化，并对全球沿海海洋生物种群和水产养殖构成重大挑战。对于所有动物来说，正常运作的免疫系统是生存的关键，也是鱼类抵御细菌和病毒感染以及治愈和从伤害中恢复的能力的关键。低氧和高温会削弱水生动物的免疫反应，因此，随着全球变暖的进程和水生低氧发生率的增加，水生动物的免疫功能可能会受到影响。尽管水生低氧对环境构成了挑战，但一些物种已经采取了有效的策略，以确保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塘中的鱼类，在这些池塘中，它们暴露在严重缺氧的间歇期，同时水温很高。这些耐低氧鱼类提供了一个很好的模型，用来研究支持耐缺氧和免疫的适应之间的相互作用。我们的目标是确定1)低氧是否激活耐低氧和不耐受鱼类的免疫反应，2)免疫系统激活是否影响耐低氧鱼类对低氧的适应性生理反应，以及3)低氧是否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.