Nanoplanktonic Protists in Marine Environments: Analysis of Natural Assemblages Using Molecualr Approaches

海洋环境中的Caron纳米浮游原生生物：用分子方法分析天然浮游生物光合和异养纳米浮游原生生物（2-20 μ m大小的微藻和原生动物）是海洋浮游生物群落的组成部分。这些单细胞真核微生物在远洋生态系统中作为初级生产者和微消费者发挥着重要作用。目前的方法计数光养nanoplankton（PNAN）和异养nanoplankton（HNAN）不能提供超过粗略的信息，这些组合的物种多样性，特定的营养作用，分类身份或地理。有一个明确的需要，应用新的方法，使PNAN和HNAN组合更彻底的特点。分子技术和新开发的定量原位杂交方法将应用于原生生物的自然组合，以评估nanoprotistan的多样性，并确定和量化主要发生的nanoprotistan物种。这项工作的主要重点将是获得序列信息（小亚基rRNA）的原生生物的天然组合，这些序列与原生生物物种在天然水样（形态种），并评估目标物种的丰度和分布，我们正在不断设计和测试寡核苷酸探针。这项工作将在实验的背景下进行，以检查的原生生物组合的物种组成的变化，以应对遏制，长期孵化（24-96小时），和富集。个体类群的人口动态的工作将开始使用寡核苷酸探针开发的异养金单胞菌属Parapatrimonas和bicosoecid种咖啡馆roenbergensis，和定量原位杂交方法。该项目将利用现代分子生物学方法，提供关于原生生物自然群落物种多样性的重要信息。此外，这项工作将提供一个工作模型系统，进一步完善和优化这些分子技术在微生物生态学的常规现场应用。

Caron NANOPLANKTONIC PROTISTS IN MARINE ENVIRONMENTS: ANALYSIS OF NATURAL ASSEMBLAGES USING MOLECULAR APPROACHES Phototrophic and heterotrophic nanoplanktonic protists (microalgae and protozoa 2-20 um in size) are integral components of marine plankton communities. These single-celled, eukaryotic microorganisms play major roles as primary producers and micro-consumers in pelagic ecosystems. Current methodologies for enumerating phototrophic nanoplankton (PNAN) and heterotrophic nanoplankton (HNAN) cannot provide more than cursory information on the species diversity, specific trophic roles, taxonomic identity or biogeography of these assemblages. There is a clear need to apply new methodologies to allow a more thorough characterization of PNAN and HNAN assemblages. Molecular techniques and a newly-developed quantitative in situ hybridization method will be applied to natural assemblages of protists in order to assess nanoprotistan diversity, and to identify and quantify the predominantly occurring nanoplanktonic protistan species. The main focus of this work will be to obtain sequence information (small subunit rRNA) from natural assemblages of protists, to relate these sequences to protistan species in natural water samples (morphospecies), and to assess the abundances and distributions of target species for which we are continually designing and testing oligonucleotide probes. This work will be conducted within the context of experiments to examine shifts in species composition of the protistan assemblage in response to containment, long-term incubation (24-96 hr), and enrichment. Work on the population dynamics of individual taxa will begin using oligonucleotide probes developed for species of the heterotrophic chrysomonad genus Paraphysomonas and the bicosoecid species Cafeteria roenbergensis, and a quantitative in situ hybridization method. The project will provide important information on the species diversity of natural protistan assemblages using modern molecular biological approaches. Additionally, this work will provide a working model system in which to further refine and optimize these molecular techniques for routine field applications in microbial ecology.