Survey of Prokaryotic Marine Plankton

小行星9401110 虽然原核生物在许多生物过程中无处不在且极其重要，但人们对天然存在的海洋种群的多样性知之甚少。 其原因包括普遍缺乏可识别的形态差异，标准鉴定所需的可培养性困难，以及正确分类的问题。 这项拟议的更新项目将调查美国不同地区和偏远海洋的浮游原核生物，通过16S rRNA基因序列对其进行分类。 这种方法提供了一个有价值的和非常广泛的系统发育分类框架，是唯一一个在这个时候，可以不培养的生物。 结果是以容易分布的序列数据的形式，并且在大型现有数据库的背景下的解释是通过系统发育分析计算机程序。 以前的工作（在我们的实验室和其他人）已经成功地将这种方法应用于大约15个海洋样品，并且已经发现了主要的新分类群（例如3个主要的古细菌群，一些潜在的门或类水平的真细菌群）。 这种新的古细菌在迄今为止研究的4个大西洋和太平洋深海样本的深海克隆中占主导地位，可能是地球上最丰富的生物群。 结果表明，这是很有可能的，其他新的主要类群，以及其他成员的更好的特点，正在等待发现的地区尚未研究。 这项建议是要将这些研究的全球范围扩大到南澳（东南印度洋）、格陵兰海、北极海洋、西北太平洋和热带太平洋西部（珊瑚礁）、阿拉伯海（西北印度洋）、南极和墨西哥湾的表层和深层沃茨，所有这些水域都远离以前用这种方法检查过的地点。 成本效益高的远程采样将由已经在研究这些领域的同事进行。 还提议对加州沿海沃茨水域的不同季节进行重复采样，以涵盖当地微生物组成的时间变化。 研究结果可用于生态学、地理学和遗传学的假设检验，但主要是作为未来此类研究的框架。

9401110 Fuhrman Although prokaryotes are ubiquitous and immensely important in numerous biological processes, the diversity of naturally occurring marine populations is poorly known. The reasons for this include a general lack of recognizable morphological differences, difficulties in culturability required for standard identification, and questions about proper classification. This proposed renewal project will survey planktonic prokaryotes in diverse U.S. and remote ocean locations, classifying them by means of 16S rRNA gene sequences. This approach has provided a valuable and extremely broad phylogenetic framework of classification, and is the only one at this time that can be done without culturing the organisms. The results are in the form of readily distributed sequence data, and interpretation within the context of a large existing database is via phylogenetic analysis computer programs. Previous work (in our lab and others) has successfully applied this approach to about 15 marine samples, and major new taxa have already been discovered (e.g. 3 major groups of archaebacteria, a few potentially phylum or class level eubacterial groups). The novel archaebacteria dominate the deep-sea clones from the 4 deep Atlantic and Pacific samples examined so far, and may be the most abundant group of organisms on Earth. Results suggest that it is highly likely that other novel major taxa, as well as additional members of better-characterized ones, are awaiting discovery in regions not yet studied. This proposal is to extend the global coverage of these studies to surface and deep waters of South Australia (SE Indian Ocean), the Greenland Sea, the North Polar Ocean, the Northwestern Pacific and Western Tropical Pacific (coral reef), the Arabian Sean (NW Indian Ocean), the Antarctic, and Gulf of Mexico, all remote from locations that have previously been examined by such approaches. Cost-effective remote sampling will be done by colleagues already studying these areas for their own work. Also proposed is repeated sampling from different seasons in California coastal waters, to cover temporal shifts in local microbial composition. The results can be used in tests of hypotheses in ecology, biogeography, and phylogeny, but primarily will serve as framework for future such studies.