Ontogeny and Dynamics of Cnidarian-Algal Symbioses

9530057共生线虫和甲藻之间的共生体广泛存在于海洋环境中。它们对造礁珊瑚和珊瑚礁营养循环的重要性已经得到了很好的证明，但令人惊讶的是，人们对共生的可能性和宿主体内虫黄藻种群的人口统计学知之甚少。理解这些过程对于理解共生是至关重要的。事实上，对温度和光照等条件的生理适应可能是由藻类共生体的种群结构所调节的。这项研究的目的是确定一种柳珊瑚共生的个体发育，该珊瑚产生平纹夜蛾幼虫。Coffroth博士将研究幼虫对原虫黄原虫的初始感染，并描述成虫群体中已建立的共生体中原虫黄原虫的种群结构。这些数据将确定观察到的宿主-藻类联合是选择(由宿主或藻类调节)、随机过程还是仅仅是宿主“栖息地”对藻类的适宜性的结果。了解虫黄藻群落的种群动态对于研究共生以及共生对环境变化的响应具有重要的意义。现在人们认识到，虫黄藻是一个多样化的类群。如果这种多样性在单个寄主群体中广泛存在，或者如果这种联系处于持续变化的状态，那么功能和生理特征的变化可能反映出藻类群落结构的变化。在这种情况下，至关重要的是检查共生的每个组成部分，并考虑珊瑚和藻类的种群动态和生态反应，以了解和保护珊瑚礁生态系统。然而，第一步是量化这种多样性，并解决这种多样性是如何建立的。

9530057 Coffroth Symbioses between cnidarians and dinoflagellates in the genus Symbiodinium are widespread in the marine environment. Their importance to reef-building corals and reef nutrient cycles is well documented, but surprisingly little is known about the ontogency of the symbiosis and the demographics of zooxanthellae populations within their hosts. An understanding of these processes is essential to understanding the symbiosis. Physiologic adaptations to conditions such as temperature and light may in fact be mediated by the demographics of the algal symbionts. The objective of this researech is to determine the ontogeny of the symbiosis in a gorgonian coral that produces azooxanthellate planulae larvae. Dr. Coffroth will examine initial zooxanthellate infection in planulae larvae and characterized the population structure of the zooxanthellae in established symbioses in adult colonies. These data will determine whether the observed host-algal association are the result of selection (mediated by the host or alga), stochastic process or simply suitability of the host "habitat" to the alga. Understanding the population dynamics of zooxanthellae communities has important ramifications for studying the symbiosis and how the symbiosis responds to environmental changes. It is now recognized that zooxanthellae are a diverse group. If this diversity is widespread among single host colonies or if the association is in a state of continual flux, then changes in functional and physiologic traits may reflect changes in the algal community structure. In this case it will be critical to examine each component of the symbiosis and consider the population dynamics and ecological responses of both the coral and the algae to understand and preserve reef ecosystems. The first step, however, is to quantify this diversity a nd address how this diversity is established.