Trojan Horses in the Marine Realm: Protist Parasite-host Dynamics in Coastal Waters

海洋领域的特洛伊木马：沿海水域中的原生生物寄生虫宿主动态

• 批准号: 1851012
• 负责人: Virginia Edgcomb
• 金额: $ 81.37万
• 依托单位: Woods Hole Oceanographic Institution
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-03-15 至 2023-02-28
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1851012&HistoricalAwards=false
• 关键词: Trojan; Horses; Marine; Realm; Protist

The ecological importance of parasitic dinoflagellates has been recognized for some time, particularly during epidemic outbreaks that cause mass mortality of their hosts, damage to aquaculture, and render commercially valuable Crustacea unpalatable. The dominate parasitic dinoflagellate group found in international global ocean surveys is referred to as MALV II Syndiniales. In the planktonic environment, the MALV II Syndiniales group not only exerts top-down controls on their prey populations, but based on their apparent ubiquity and abundance, they likely shape the pools of nutrients in marine water columns. Data on cultured samples reveals this hyper-diverse group can infect a wide range of protist hosts, as well as copepods, and fish larvae. Gaps in knowledge of the specificity and dynamics of the host-parasite interactions contribute to difficulties in estimating the impacts on the coastal ecosystems. In this project, researchers combine novel methods in microscopy, genomics, and chemistry to track host-parasite dynamics at a coastal site over an annual cycle followed by modeling to assess the impacts on microbial ecosystem dynamics. The researchers will engage undergraduate and high school students in field and laboratory research activities. In addition, support for a graduate student is included along with plans to disseminate the research results more broadly through publications and presentations.Syndiniales parasitism is a widespread, albeit under-studied symbiotic interaction in the marine environment and little is known about regulation of protist populations by these parasites. In spite of their cosmopolitan distribution in the global ocean and their apparent abundance in molecular datasets of protist marker genes, little is known about the ecology of these parasites and almost no genomic data exists for them. In this project, the researchers combine high-resolution sampling, water chemistry (including nutrients) analyses, molecular marker gene analyses, fluorescence in situ hybridization, single cell genomics, and modeling to produce the first focused assessment of host-MALVII parasite dynamics and ecology at the community level in a coastal marine ecosystem. The researchers will evaluate temporal dynamics of host and parasite diversity and will examine temporal variation in levels of infection of the protist community and host-parasite specificity using high-resolution sampling in Salt Pond, Falmouth, MA, and in situ hybridization microscopy. Molecular approaches include amplicon tag high throughput sequencing, leveraging the emerging third generation sequencing technology, Oxford Nanopore's MinION to elucidate host-parasite identities. The researchers will also apply advances in single-cell genome sequencing to inform on strain-specific genome content, including the molecular mechanisms underpinning protist parasitism. Contributions to pools of particulate and dissolved organic matter will be estimated for several of the most commonly infected host taxa in Salt Pond using laboratory experiments, providing the first set of values for modeling impacts of Syndiniales parasitism on pools of organic and inorganic nutrients.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

寄生性腰鞭毛虫的生态重要性已经被认识了一段时间，特别是在流行病爆发期间，导致其宿主的大规模死亡，对水产养殖造成损害，并使具有商业价值的甲壳纲动物变得难以接受。在国际全球海洋调查中发现的主要寄生甲藻群被称为MALV II Syndiniales。在浮游环境中，MALV II Syndiniales组不仅对它们的猎物种群施加自上而下的控制，而且基于它们明显的普遍性和丰富性，它们可能会塑造海洋水柱中的营养池。培养样本的数据显示，这种高度多样化的群体可以感染各种原生生物宿主，以及桡足类和鱼类幼虫。对宿主-寄生虫相互作用的特性和动态的了解不足，导致难以估计对沿海生态系统的影响。在这个项目中，研究人员结合联合收割机在显微镜，基因组学和化学的新方法，跟踪主机寄生虫动态在沿海地区的一个年度周期，然后建模，以评估对微生物生态系统动态的影响。研究人员将让本科生和高中生参与实地和实验室研究活动。此外，支持一名研究生包括沿着计划更广泛地传播研究成果，通过出版物和presentation.Syndiniales寄生是一个广泛的，虽然研究不足的共生相互作用在海洋环境中，很少有人知道这些寄生虫的原生生物种群的调节。尽管它们在全球海洋中分布广泛，并且在原生生物标记基因的分子数据集中明显丰富，但对这些寄生虫的生态学知之甚少，几乎没有它们的基因组数据。在这个项目中，研究人员结合联合收割机高分辨率采样，水化学（包括营养物质）分析，分子标记基因分析，荧光原位杂交，单细胞基因组学和建模，以产生在沿海海洋生态系统的社区水平上的宿主-MALVII寄生虫动态和生态的第一个重点评估。研究人员将评估宿主和寄生虫多样性的时间动态，并将使用马萨诸塞州法尔茅斯盐池的高分辨率采样和原位杂交显微镜检查原生生物群落感染水平和宿主-寄生虫特异性的时间变化。分子方法包括扩增子标签高通量测序，利用新兴的第三代测序技术，牛津纳米孔的MinION来阐明宿主-寄生虫身份。研究人员还将应用单细胞基因组测序的进展来了解菌株特异性基因组内容，包括支持原生生物寄生的分子机制。 利用实验室实验，将估计盐池中几种最常见的受感染宿主类群对颗粒物和溶解有机物池的贡献，为模拟Syndiniales寄生对有机和无机营养物池的影响提供了第一套价值。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响进行评估，被认为值得支持审查标准。

项目成果

Parasitic infections by Group II Syndiniales target selected dinoflagellate host populations within diverse protist assemblages in a model coastal pond

II 组 Syndiniales 的寄生虫感染针对模型沿海池塘中不同原生生物组合内选定的甲藻宿主种群

• DOI: 10.1111/1462-2920.15977
• 发表时间: 2022
• 期刊: Environmental Microbiology
• 影响因子: 5.1
• 作者: Sehein, Taylor R.;Gast, Rebecca J.;Pachiadaki, Maria;Guillou, Laure;Edgcomb, Virginia P.
• 通讯作者: Edgcomb, Virginia P.