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，预计大气中二氧化碳（CO2）的增加被认为是对全世界海洋系统的主要威胁。珊瑚礁对这些预计的地球气候变化非常敏感，其生长持续减少，以及生活在多种宿主动物（包括石珊瑚、软珊瑚和海葵）中的藻类（共生菌）之间的共生关系受到破坏（也称为白化）。虽然已经收集了很多关于酸化如何影响石珊瑚的信息，但关于酸化和温度对其他共生珊瑚虫的相互作用的了解却少得多。为此，本提案将研究二氧化碳和温度升高对模型海葵（Aiptasia pallida）的长期影响，同时包含四种不同的共生菌基因型。该项目的主要目标是：(1)确定暴露在升高的二氧化碳和温度下，动物在分子和生理过程中适应环境的敏感性和能力；(2)评估适应环境的成年动物将印记生理特征赋予（或转移）给下一代无性后代的程度。将对每种动物/藻类组合（holobiont）进行一系列长期实验，以收集初始（3个月）的应激标记和基因组数据，然后在一年的时间里跟踪动物的反应和无性繁殖。通过跟踪每个全息生物的恢复情况，然后在高二氧化碳环境中反复暴露于高温环境中，来测量增强复原力或适应能力的可能性。该项目将梳理出压力、驯化或改良的精细尺度机制，这些机制可能随着藻类基因型和宿主动物反应的功能而变化，以及环境印记可能使繁殖体预先适应的程度。项目结果将提供关于未来酸化和变暖将如何影响刺胞-藻类共生的信息，以及它们在有机体、代谢、基因组和表观遗传尺度上的应激反应过程中的灵活性的基本概况。除了培养一名博士后学者和几名研究生外，该项目还将通过为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性不足群体的参与。公众宣传工作将包括一个儿童“游戏”教育展览，以及几个实际的研究演示，其中包括海葵生物学和共生的元素，这些将在特拉华大学的年度“海岸日”节日上展示。研究工作也将有助于进一步发展在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.