Collaborative Research: Analysis of a Protist Assemblage of the Coastal Ctenophore Mnemiopsis leidyi

项目摘要本项目的重点是表征，繁殖，和功能的影响，一个特定的组合epicommensal原生动物与叶状栉水母，Mnemiopsis leidyi，一个关键的捕食者的海洋沿海浮游生物群落从墨西哥湾沿着大西洋海岸到新英格兰。 来自四个机构的一组合作研究人员正在记录物种多样性、组合中每个成员的相对物种丰度、地理范围和这一组合的感染力。 这些合作实验室对每一个当地环境都有具体的了解，并具有生态学、生命史、细胞生物学、显微镜和分子生物学方面的科学专门知识，正在全面研究一种凝胶状捕食者与表生微生物的相互作用。正在确定每个采集点的盐度、温度、溶解氧、叶绿素和浊度，以便将具体的物理因素与生物组合的出现联系起来。 这一信息将确定环境参数对组合物（或具体组成部分）的影响程度;反过来，也将确定这一组合物是否可用作环境质量标志。 了解微生物-宿主相互作用的范围对于更完整地了解拟记忆藻的生物学至关重要。 拟记忆虫通过贪婪地捕食浮游动物种群来改变群落结构，直到这种资源变得仅限于其他捕食者物种（即，鱼）。 拟记忆线虫也是一种全球入侵生物，已证明其有能力破坏全球沿海社区的营养结构，并造成严重的经济后果。 原生生物密集群落可能改变拟记忆虫的繁殖能力和摄食能力，并可能在新的环境中转移到新的宿主。 因此，了解这种组合的生物学，其对宿主的影响，以及其侵染替代物种的能力，可以阐明拟记忆体入侵新环境的机制和影响。正在通过分子系统发育技术、传统原生动物学鉴定方法和细胞超微结构数据相结合的方法获得该组合的全面概况，以提供关于每个组成物种的详细信息。 正在研究环境中细胞的来源（即是否来自水柱或底栖群落），以及个别物种是否正在转移到更高营养级的捕食者，如较大的凝胶状捕食性栉水母（例如，Bero）或鱼。这项研究的结果提供了一个数据库的组成，地理范围，原产地和环境参数的这一组合，并正在形成的基础，建立这一组合作为一个模型系统，为今后的研究领域广泛多样的细胞间的相互作用和机制的水生群落结构的维护，包括对沿海环境的影响和可能的控制手段的潜力。 这项研究要求每个研究者所在地的本科生和研究生。 PI正在吸引女性和男性非洲裔美国人，西班牙裔，亚洲和美洲原住民学生参加他们的课程。

Project summary This project focuses on the characterization, phylogeny, and functional impact of a specific assemblage of epicommensal protists associated with the lobate ctenophore, Mnemiopsis leidyi, a keystone predator of marine coastal planktonic communities extending from the Gulf of Mexico along the Atlantic Coast to New England. The species diversity, relative species abundance of each member of the assemblage, geographic range and infectivity of this assemblage is being documented by a team of collaborating researchers from four institutions. The collaborative laboratories have the specific knowledge of each of the local environments and the scientific expertise in ecology, life history, cell biology, microscopy and molecular biology and are making a comprehensive study of epibiotic microbial interactions with a gelatinous predator. Salinity, temperature, dissolved oxygen, chlorophyll and turbidity are being determined at each collection site in order to correlate specific physical factors with the occurrence of the assemblage. This information will determine to what degree the assemblage (or specific components) is affected by environmental parameters; and conversely, to establish whether this assemblage can be used as an environmental quality marker. Understanding the range of the microbe-host interaction is critical to a more complete understanding of the biology of Mnemiopsis. Mnemiopsis alters community structure through voracious predation on zooplankton populations to the point where this resource becomes limiting to other predator species (i.e., fish). Mnemiopsis is also a globally invasive organism that has demonstrated its capacity to disrupt the trophic structure of coastal communities worldwide, with severe economic consequences. Dense protist assemblages may alter reproductive capacity and feeding in Mnemiopsis, and could be transferred to new hosts in new environments. As such, understanding the biology of this assemblage, its impact on the host, and its capacity to infest alternate species, could illuminate the mechanisms and effects of Mnemiopsis invasion into a new environment. Comprehensive profiles of the assemblage are being obtained by a combination of molecular phylogenetic techniques, conventional protozoological identification methods and cellular ultrastructural data to provide detailed information about each component species. The source of the cells within the environment (i.e. whether derived from the water column or benthic communities) is being studied and whether individual species is being transferred to higher trophic level predators such as larger gelatinous predatory ctenophores (e.g., Bero) or fish. Results of this study are providing a database of the composition, geographic range, origin and environmental parameters of this assemblage and is forming the basis for establishing this assemblage as a model system for future studies in areas as widely diverse as cell-cell interactions and mechanisms of maintenance of aquatic community structure, including potential for effects on the coastal environment and possible means of control. This study is requiring undergraduate and graduate students at each investigator's location. The PIs are attracting female and male African-American, Hispanic, Asian and Native American students to their programs.