Collaborative Research: Comparative and Quantitative Studies of Protistan Molecular Ecology and Physiology in Coastal Antarctic Waters

光养和异养原生生物在极端冷水环境中无处不在，它们对能量的生产和利用以及元素的循环至关重要。原生生物在南极食物网中的优势地位表明，这些单细胞真核生物在生态和生物地球化学方面发挥着重要作用。了解这些群落的结构和多样性，以及使这些群落在海洋温度下限附近蓬勃发展的适应性，对于生物海洋学和理解我们星球上生命的活动和进化至关重要。原生生物组合的多样性传统上是用显微镜和形态表征来研究的。由于这种方法的繁琐和缺乏与大多数小型原生生物相关的分类特征，这些方法对于这些群落的生态学研究是不够的。利用基因序列对天然原生生物进行鉴定和定量的分子方法为这一问题提供了解决方案。本项目将通过对南极罗斯海海水和海冰栖息地中原生物群落的分子和生理研究，研究原生物群落结构、种群丰度和对极端寒冷生活的适应问题。研究将主要集中在具有重要生态学意义但目前尚无相关资料的吞噬原生生物（原生动物）。本研究旨在为南极沿海原生生物群落的生物多样性提供新的认识，为南极沿海原生生物群落的生态学研究提供工具，并为南极沿海极端冷水环境下原生生物的基本生理过程提供基准数据。

Gast0125833Phototrophic and heterotrophic protists are ubiquitous in extreme cold-water environments where they are central to the production and utilization of energy and the cycling of elements. The dominance of protists in Antarctic food webs indicates major ecological and biogeochemical roles for these unicellular eukaryotes. Understanding the structure and diversity of these communities, and the adaptations that allow these assemblages to flourish near the lower limit of temperature in the ocean, is of fundamental importance to biological oceanography and to understanding the activities and evolution of life on our planet. The diversity of protistan assemblages has traditionally been studied using microscopy and morphological characterization. Due to the tedious nature of this approach and the inherent lack of taxonomic characters associated with most small protists, these approaches are inadequate for ecological studies of these communities. Molecular methods that utilize gene sequences for the identification and quantitation of naturally occurring protists offer a solution to this problem. This project will address issues of protistan community structure, population abundance, and adaptation to life in extreme cold through molecular and physiological studies on assemblages in the seawater and ice habitats of the Ross Sea, Antarctica. Research will focus primarily on species of phagotrophic protists (protozoa) which are ecologically important but for which no information currently exists. The work is designed to contribute new understanding concerning the biodiversity of protistan assemblages of coastal Antarctica, provide tools for ecological studies of these assemblages, and produce benchmark data on the basic physiological processes of protistan species in this extreme cold-water environment.