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

本项目的重点是一组特定的表层原生动物的特征、系统发育和功能影响，这些原生生物与分叶鞭毛虫有关，是从墨西哥湾沿大西洋沿岸延伸到新英格兰的海洋沿海浮游生物群落的一种关键捕食者。来自四个机构的一组合作研究人员正在记录这一组合的物种多样性、每个组合成员的相对物种丰度、地理范围和传染性。合作实验室拥有当地环境的具体知识和生态学、生命史、细胞生物学、显微镜和分子生物学方面的科学专业知识，并正在全面研究表生微生物与胶状捕食者的相互作用。每个采集点都在测定盐度、温度、溶解氧、叶绿素和浊度，以便将特定的物理因素与组合的出现联系起来。这些信息将确定组件(或特定组件)受环境参数影响的程度；反之，确定该组件是否可用作环境质量标记。了解微生物-宿主相互作用的范围对于更全面地了解Mnmiopsis的生物学至关重要。通过对浮游动物种群的贪婪捕食，毛虾改变了群落结构，以至于这种资源仅限于其他捕食者物种(即鱼类)。姆米普斯也是一种全球入侵生物，已证明它有能力破坏世界各地沿海社区的营养结构，造成严重的经济后果。密集的原生生物组合可能会改变其繁殖力和取食能力，并可能在新的环境中转移到新的寄主。因此，了解这种群落的生物学特性，它对宿主的影响，以及它侵染替代物种的能力，可以解释姆氏假丝酵母入侵新环境的机制和影响。通过结合分子系统发育技术、传统的原生动物鉴定方法和细胞超微结构数据，正在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生物群落)，以及个别物种是否正在被转移到营养级别较高的捕食者，如较大的胶状捕食性线虫(例如，贝罗)或鱼类。这项研究的结果提供了这一组合的组成、地理范围、来源和环境参数的数据库，并为建立这一组合作为未来研究的模式系统奠定了基础，研究领域广泛，包括细胞-细胞相互作用和水生群落结构的维持机制，包括对沿海环境的潜在影响和可能的控制手段。这项研究要求每个研究人员都有本科生和研究生。PI正在吸引非洲裔美国人、西班牙裔美国人、亚洲人和美洲原住民的女性和男性学生参加他们的项目。

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.