Dissertation Research: The Effects of Elevated Temperature on Symbiotic Dinoflagellates: Possible Sites of Damage and Protection and Coral Bleaching

热带地区的大多数造礁珊瑚都含有高密度的共生鞭毛藻共生藻，通常被称为虫黄藻。这些藻类对单个珊瑚群的健康至关重要，也是总体初级生产力的主要贡献者，使这些珊瑚礁能够在它们所居住的低营养水域中蓬勃发展。最近与水温升高有关的大范围白化事件在世界范围内发生，珊瑚以惊人的速度失去了虫黄藻。虽然已经证明这些藻类受到温度升高的不利影响，但导致光合能力丧失的细胞事件的确切机制尚未确定。本研究的目的是：(1)研究不同类型的虫黄藻在体外对光系统II的特定多肽在生化、翻译和转录后水平上是否表现出不同程度的损伤或保护，以及(2)确定在不同温度变化水平的栖息地中生活的不同宿主中是否存在类似的过程。这些破坏和保护机制似乎在决定生态分布以及环境相关压力期间藻类无脊椎动物群落的最终命运方面发挥了重要作用。

Fitt 9702032 The majority of reef building corals throughout the tropics contain high densities of the symbiotic dinoflagellate Symbiodinium sp.commonly called zooxanthellae. These algae are vital to the health of the individual coral colony as well as major contributors to the overall primary productivity that allows these reefs to flourish in the oligotrophic waters in which they reside. Recent wide spread bleaching events, correlated to elevated water temperatures, have occurred world wide in which corals have lost their zooxanthellae at alarming rates. While it has been shown that these algae are adversely effected by elevated temperature, the precise mechanisms of the cellular events that lead to a loss in photosynthetic ability have yet to be established. Objectives of this proposal are: (1) to investigate if different types of zooxanthellae in vitro exhibit differential levels of damage or protection to specific polypeptides of photosystem II at the biochemical, translational, and post-transcriptional level, and (2) to determine if similar processes exist for dinoflagellates living in different hosts that reside within habitats with different levels of temperature variability. These mechanisms of damage and protection appear to play a major role in determining the ecological distribution, as well as the ultimate fate of algalinvertebrate assemblages during periods of environmentally relevant stress.