Understanding how global warming will select for zooxanthellae phenotypes

共生甲藻（英语：Symbiodinium）是一种分布于热带和亚热带的世界性甲藻属，也是珊瑚礁生态系统中不可或缺的一员。作为珊瑚和其他珊瑚礁生物的专性内共生体，共生藻通过促进宿主的新陈代谢和生长，是珊瑚礁初级生产的主要贡献者。在这种微妙的共生关系中，共生体作为自养生物发挥作用，释放其大部分光合产物作为宿主的食物，而珊瑚提供保护，稳定的环境和藻类用于生长的代谢废物。近年来，由于海洋温度上升，这种关系的脆弱性变得越来越明显。珊瑚“漂白”事件，即珊瑚释放共生体以应对压力的过程，正在成为全球环境危机。在这个过程中，共生藻会受到压力，释放活性氧，失去光合作用能力。长时间接触会造成不可逆转的损害，并将虫黄藻从宿主体内排出。持续和经常发生的白化事件可能对珊瑚礁健康造成灾难性后果，导致珊瑚群落死亡和营养结构崩溃。然而，一些珊瑚似乎可以承受这些事件而不受伤害，实验室研究表明，一些共生藻可以耐受热应力。虽然最近的工作已经揭示了巨大的遗传多样性的共生藻在珊瑚礁生态系统中，如何多样性与压力tolerances.The本研究的目的是描述共生藻的遗传多样性的关系，以应力表型在自由生活和共生菌株，并确定一些菌株如何耐受高温应力和抗漂白在其主机。另一个目标是找到应激敏感的基因型标记，可用于评估珊瑚礁的健康和对热应激的敏感性。使用生物物理，分子生物学和生物化学测定的组合，PI建议采样最大数量的共生藻菌株，以实验确定基因型与表型多样性的关系。更广泛的影响包括通过教育公众了解珊瑚生理学来提高海洋科学素养，并解释人类活动如何影响海洋生物的健康。教育和推广活动将通过罗格斯大学、自由科学中心和COSEE-West之间目前的伙伴关系来开展。这项研究也可能对珊瑚礁管理产生影响。 最后，研究结果将作出重大贡献的生态学和进化的共生藻的基础理解。

Symbiodinium (= zooxanthellae) is a cosmopolitan dinoflagellate genus of tropical and subtropical latitudes, and an integral member of coral reef ecosystems. As the obligate endosymbionts of corals and a variety of other reef organisms, Symbiodinium is the main contributor to coral reef primary production by fueling their host's metabolism and growth. In this delicate symbiosis the symbiont functions as an autotroph, releasing most of its photosynthetic products as food for their host, while the corals provide protection, a stable environment, and metabolic waste that the algae use to grow. The fragility of this relationship has become increasingly apparent in recent years due to rising ocean temperatures. Coral 'bleaching' events, a process by which corals release their symbionts in response to stress, are becoming a global environmental crisis. During this process, Symbiodinium becomes stressed, releasing reactive oxygen species and losing photosynthetic abilities. Prolonged exposure causes irreversible damage and expulsion of zooxanthellae from their hosts. Persistent and recurrent bleaching events can have catastrophic consequences to coral reef health, resulting in the death of coral colonies and a collapse of trophic structure. However, some corals appear to withstand these events unharmed, and laboratory research has shown that some Symbiodinium are tolerant of heat stress. While recent work has revealed a vast genetic diversity of Symbiodinium in coral reef ecosystems, how the diversity is related to stress tolerance is poorly understood.The objectives of this research are to describe the relationship of Symbiodinium genetic diversity to stress phenotypes in both free-living and symbiotic strains, and to determine how some strains tolerate high temperature stress and resist bleaching in their hosts. Another goal is to find stress-sensitive genotype markers that can be used to evaluate coral reef health and susceptibility to heat stress. Using a combination of biophysical, molecular biological and biochemical assays, the PIs propose to sample the largest number of Symbiodinium strains to date, to experimentally determine how genotype is related to phenotype diversity. The broader impacts include advancing Ocean Science Literacy by educating the general public about coral physiology, and explaining how anthropogenic activities may impact the health of marine organisms. Education and outreach activities will be developed through current partnerships between Rutgers, the Liberty Science Center, and COSEE-West. The research may also have implications for coral reef management. Finally, results will make significant contributions to the fundamental understanding of the ecology and evolution of Symbiodinium.