Ocean Acidification: Understanding the Impact of CO2 and Temperature on the Physiological, Genetic, and Epigenetic Response of a Model Sea Anemone System with Different Symbionts

由于海洋酸化和海洋温度上升，大气中二氧化碳(CO2)的预计上升被认为是对世界各地海洋系统的主要威胁。珊瑚礁对地球气候的这些预期变化非常敏感，生长继续减少，生活在包括石珊瑚、软珊瑚和海葵在内的各种宿主动物中的藻类(共生动物)之间的共生关系中断(也称为漂白)。虽然关于酸化如何影响石珊瑚的信息已经收集了很多，但关于酸化和温度对其他共生珊瑚虫的交互影响的了解却相当少。为此，这项建议将调查二氧化碳和温度升高对模式海葵Aiptasia pallida的长期影响，同时拥有四种不同的共生生物。该项目的主要目标是(1)确定在二氧化碳和温度升高的情况下，分子和生理过程中的适应能力和敏感度，以及(2)评估驯化的成年动物可以将印记的生理特征赋予(或转移)下一代无性后代的程度。为了收集最初(3个月)的应激标记和基因组数据，将对每种动物/藻类组合(Holobion T)进行一系列长期实验，然后在一年内跟踪几代动物的反应和无性繁殖。通过跟踪每个全息细菌的恢复情况，然后重复暴露在高温下，同时保持在高二氧化碳中，来衡量增强适应能力或适应能力的可能性。这个项目将梳理出压力、驯化或改善的精细尺度机制，这些机制可能会随着藻类基因和宿主动物的反应而变化，以及环境印记可能在多大程度上影响适应前的繁殖。项目成果将提供有关未来酸化和变暖将如何影响蛇毒-藻类共生体的信息，以及它们在有机体、新陈代谢、基因组和表观遗传尺度上应激反应过程中灵活性的基本概况。除了培训一名博士后学者和几名研究生外，该项目还将通过向来自不同大学的几名本科生提供实验室经验，加强科学发现和代表不足群体的参与。公众推广工作将包括一个儿童“游戏”教育展览，以及几个结合海葵生物学和共生元素的动手研究演示，将在特拉华大学一年一度的“海岸日”艺术节上展示。研究工作还将有助于进一步发展特拉华大学特拉华生物技术中心的NSF-EPSCoR基础设施。

The projected rise in carbon dioxide (CO2) in the atmosphere is considered a primary threat to marine systems throughout the world due to both ocean acidification and rising ocean temperatures. Coral reefs are very sensitive to these projected changes in the earth's climate, with continued losses in growth as well as disruption (also known as bleaching) in the symbiotic relationship between the algae (Symbiodinium) living within a diversity of host animals, including stony corals, soft corals and sea anemones. While much information has been gleaned as to how acidification may affect stony corals, considerably less is known about the interactive effects of acidification and temperature to other symbiotic anthozoans. To this end, this proposal will investigate the long-term impacts of elevated CO2 and temperature on the model sea anemone, Aiptasia pallida, while harboring four different genotypes of Symbiodinium. The primary goals of this project are (1) to determine the sensitivity and capacity for acclimation in molecular and physiological processes while exposed to elevated CO2 and temperature, and (2) to assess the degree to which acclimated adult animals may confer (or transfer) an imprinted physiological characteristic to the next generation of asexual offspring. A series of long-term experiments will be conducted with each animal/algal combination (holobiont) in order to collect initial (3 month) stress markers and genomic data and then follow animal response and asexual reproduction through several generations for one year. The possibility for enhanced resilience or acclimation will be measured by tracking the recovery of each holobiont, followed by repeated exposure to elevated temperature while held in high CO2. This project will tease apart fine scale mechanisms of stress, acclimation, or amelioration that may vary as a function of algal genotype and host animal response, and the degree to which environmental imprinting may pre-acclimate propagules. Project results will provide information regarding how future acidification and warming will affect cnidarian-algal symbioses, and the fundamental profile of their flexibility in stress response processes across organismal, metabolic, genomic and epigenetic scales. In addition to training one postdoctoral scholar and several graduate students, this project will enhance scientific discovery and participation of underrepresented groups through laboratory experiences offered to several undergraduates from different universities. Public outreach efforts will include a children's 'play'-educational exhibit, as well as several hands-on research demonstrations incorporating elements of sea anemone biology and symbioses which will be presented at the University of Delaware's annual "Coast Day" festival. Research efforts will also contribute to the further development of the NSF-EPSCoR infrastructure in the Delaware Biotechnology Center at the University of Delaware.