MIP: Protist-Prokaryote Symbioses in Bathyal Sulfidic Sediments: Santa Barbara Basin Flagellates and Ciliates

在微观研究的基础上，确定了一个丰富多样的原生生物群落出现在圣巴巴拉盆地（SBB）的贫氧、富硫化物深海沉积物中。 这些真核生物中的大多数，其中许多属于新的科学分类群，港口原核生物在一个假定的共生协会。 目前，这些相关原核生物的身份和生理作用/代谢活动尚不清楚。 本项目的目标是调查四个特定的原核生物-真核生物协会（推定的共生体），在SBB中观察到在以前的研究中，通过阐明主机共生体的身份和功能，这些协会使用的组合基于文化的，分子，细胞生物学和地球化学方法。 这些方法包括rRNA和功能基因的分析、靶向rRNA的荧光原位杂交研究（FISH）、分子鉴定和显微放射自显影的组合（MAR-FISH）以及显微镜分析（SEM、TEM）。 将在两次为期5天的海洋学航行中收集材料。待分析的特定关联涉及以下宿主：Calkinsia aureus（鞭毛虫与外生生物）、Euglenoid sp.（鞭毛虫与外生生物）、Metopus verrucosus（纤毛虫与外生生物）和Metopus halophila或Parablepharisma sp.（纤毛虫与内生生物或外生生物）。 这些假定的内、外共生体被假设具有多种代谢能力。这个项目将大大提高我们的知识，原核生物真核生物协会在一个研究不足的海洋栖息地。 大多数SBB真核生物，其中许多尚未被描述，与原核生物似乎是推定的共生体。 这些相关原核生物的生理学、系统学和代谢尚不清楚。 阐明在这种硫化物和微氧/缺氧深海环境中微生物群落内原核生物和真核生物之间的共生关系，将揭示共生微生物在适应这些环境中所起的作用，以及它们对该环境的生物地球化学的潜在影响。 此外，共生体是通过引入新的遗传物质进行进化的潜在载体，因此代表了物种形成的可能机制。 共生也可能允许生态位和栖息地的扩张，这可能是真核生物早期进化和多样化的主要因素。 该项目将包括本科生和研究生、K-12教师和普通公众的积极参与，以及通过基于互联网的知识网络、在广泛发行的专业科学期刊上发表文章、教育活动（例如，为中学教师和研究科学家举办的讲习班）和研讨会。

On the basis of microscopic studies it is established that an abundant and diverse protistan community occurs in the oxygen-depleted, sulfide-enriched deep-sea sediments of the Santa Barbara Basin (SBB). The majority of these eukaryotes, many of which belong to taxa that are new to science, harbor prokaryotes in a putative symbiotic association. At present, the identity and physiological role/metabolic activities of these associated prokaryotes are unknown. The goal of this project is to investigate four specific prokaryote-eukaryote associations (putative symbioses) that were observed in SBB during previous studies by elucidating the host-symbiont identities and functions of these associations using a combination of culture-based, molecular, cell biological, and geochemical methods. These approaches include analyses of rRNA and functional genes, fluorescent in situ hybridization studies targeting rRNA (FISH), a combination of molecular identification and microautoradiography (MAR-FISH), and microscopical analyses (SEM, TEM). Material will be collected on two 5-day oceanographic cruises. The specific associations to be analyzed involve the following hosts: Calkinsia aureus (flagellate with ectobionts), Euglenoid sp. (flagellate with ectobionts), Metopus verrucosus (ciliate with ectobionts), and Metopus halophila or Parablepharisma sp. (ciliates with endobionts or ectobionts). These putative endo- and ectosymbionts are hypothesized to have a variety of metabolic capabilities. This project will significantly enhance our knowledge of prokaryote-eukaryote associations in a poorly studied marine habitat. The majority of the SBB eukaryotes, many of which are yet to be described, have associations with prokaryotes that appear to be putative symbionts. The physiology, systematics, and metabolism of these associated prokaryotes are unknown. Elucidating the symbiotic relationships between prokaryotes and eukaryotes within the microbial community in this sulfidic and micro-oxic/anoxic deep-sea environment will shed light on the role that symbioses play within microbial consortia in their adaptation to these environments, and their potential impact on the biogeochemistry of that environment. Further, symbioses are potential vehicles for evolutionary change through the introduction of new genetic material, and therefore represent possible mechanisms of speciation. Symbioses may also allow for niche and habitat expansion, possibly a major factor in the early evolution and diversification of eukaryotes. This project will include active involvement of undergraduate and graduate students, K-12 teachers, and the lay public, as well as broad dissemination of results via internet-based knowledge networks, publications in widely-circulated professional scientific journals, educational activities (e.g., workshops for both secondary school teachers and research scientists), and seminars.