Interacting Stressors: Metabolic Capacity to Acclimate under Ocean Warming and CO2-Acidification in Early Developmental Stages of Antarctic Fishes

南大洋包含了非凡的海洋生物多样性。许多南极海洋生物在稳定、寒冷的海洋条件下进化，对环境波动的反应能力有限。迄今为止，对南极鱼类生理极限的研究主要集中在成年生命阶段。然而，早期生命阶段可能对环境变化更敏感，因为他们可能需要优先考虑能量的生长和发育，而不是维持生理平衡和完整性-即使在压力条件下。该项目将研究南极幼鱼（胚胎、幼体和幼鱼）在分子、细胞和生理水平上对海洋条件变化作出反应以使其能够生存的具体机制。其目的是提供一个统一的框架，将具有不同生长和发育速率的不同物种的环境变化，基因表达，代谢和生物体性能联系起来。有一个多样化和强大的教育和推广计划与研究工作，将达到学生，教师，青年科学家，社区成员和政府官员在地方和地区规模。极地物种已经被确定为极易受到全球变化的影响。然而，到目前为止，还没有统一的框架将环境变化与生物体的表现联系起来，部分原因是大多数物种缺乏对压力如何在分子，生物化学和生理水平上相互作用的机械理解。在海洋环境中，这种信息的缺乏限制了我们准确预测变暖和二氧化碳酸化对极地物种影响的能力，因此无法将气候模型预测与人口健康预测联系起来。这项研究将评估代谢能力（即使能量供应与能量需求相匹配的能力）是否限制了南极鱼类适应海洋变暖和CO2酸化的同时压力的能力。如果物种在暴露于压力源后无法重建代谢稳态，增加的能量成本可能会导致生理表现，生物体适应性和生存能力下降。这种能量不匹配的假设将在一个多物种的方法，侧重于生命的早期阶段进行测试，因为成长中的青少年可能比成年人更容易受到能量限制，而不同的物种是有针对性的，以了解物候和生活史特征的差异如何影响代谢可塑性。这项研究将提供一个机制整合的基因表达和代谢模式，并在细胞和整个生物体水平的代谢反应，以广泛了解鱼类的代谢可塑性。 该研究与“解码南极生物和生态系统生物适应和反应的基因组和转录组学基础”这一主题相一致，这是美国国家科学院在其文件“NSF投资南极和南大洋研究的战略愿景”中确定的三大主题之一。此外，该项目通过三种主要方式提高更广泛社区的科学素养来建立环境管理和意识：首先，它将通过支持一名博士生，一名博士后学者和两名本科生来增加参与环境科学研究的学生的多样性，并促进来自传统上在环境生物学中代表性不足的群体的年轻学生的培训。其次，该项目将参与加州大学戴维斯分校的OneClimate计划，该计划利用社区的专业知识，发展有关气候变化，科学和社会的广泛观点，并让K-12学生，政府官员以及当地和全州社区参与南极研究，生物适应以及正在进行的和潜在的未来变化。最后，将与NSF资助的教育项目APPLES（北极植物物候学：通过极地科学学习）合作举办夏季研讨会，让教师和K-12学生参与极地科学。该奖项反映了NSF的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。

The Southern Ocean contains an extraordinary diversity of marine life. Many Antarctic marine organisms have evolved in stable, cold ocean conditions and possess limited ability to respond to environmental fluctuations. To date, research on the physiological limits of Antarctic fishes has focused largely on adult life stages. However, early life stages may be more sensitive to environmental change because they may need to prioritize energy to growth and development instead of maintenance of physiological balance and integrity- even under stress conditions. This project will examine the specific mechanisms that young (embryos, larvae and juveniles) Antarctic fishes use to respond to changes in ocean conditions at the molecular, cellular and physiological levels, so that they are able to survive. The aim is to provide a unifying framework for linking environmental change, gene expression, metabolism and organismal performance in different species that have various rates of growth and development. There is a diverse and robust education and outreach program linked with the research effort that will reach students, teachers, young scientists, community members and government officials at local and regions scales. Polar species have already been identified as highly vulnerable to global change. However as yet, there is no unifying framework for linking environmental change to organismal performance, in part because a mechanistic understanding of how stressors interact at the molecular, biochemical and physiological level is underdeveloped is lacking for most species. In the marine environment, this paucity of information limits our capacity to accurately predict the impacts of warming and CO2-acidification on polar species, and therefore prevents linking climate model projections to population health predictions. This research will evaluate whether metabolic capacity (i.e. the ability to match energy supply with energy demand) limits the capacity of Antarctic fishes to acclimate to the simultaneous stressors of ocean warming and CO2-acidification. If species are unable to reestablish metabolic homeostasis following exposure to stressors, increased energetic costs may lead to a decline in physiological performance, organismal fitness, and survival. This energy-mismatch hypothesis will be tested in a multi-species approach that focuses on the early life stages, as growing juveniles are likely more vulnerable to energetic constraints than adults, while different species are targeted in order to understand how differences in phenology and life history traits influence metabolic plasticity. The research will provide a mechanistic integration of gene expression and metabolite patterns, and metabolic responses at the cellular and whole organism levels to broadly understand metabolic plasticity of fishes. The research is aligned with the theme "Decoding the genomic and transcriptomic bases of biological adaptation and response across Antarctic organisms and ecosystems" which is one of three major themes identified by the National Academy of Sciences in their document "A Strategic Vision for NSF Investments in Antarctic and Southern Ocean Research". Additionally, this project builds environmental stewardship and awareness by increasing science literacy in the broader community in three main ways: First it will increase the diversity of students involved in environmental science research by supporting one PhD student, one postdoctoral scholar and two undergraduate students and promoting the training of young students from groups traditionally underrepresented in environmental biology. Second, the project will participate in UC Davis's OneClimate initiative, which leverages the community's expertise to develop broad perspectives regarding climate change, science and society, and engage K-12 students, government officials, and local and statewide communities on topics of Antarctic research, organismal adaptation as well as ongoing and potential future changes at the poles. Lastly, summer workshops will be conducted in collaborations with the NSF-funded education program APPLES (Arctic Plant Phenology: Learning through Engaged Science), to engage teachers and K-12 students in polar science.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.