Collaborative Research: Investigations into microbially mediated ecological diversification in sponges

合作研究：微生物介导的海绵生态多样化研究

• 批准号: 1929293
• 负责人: Christopher Freeman
• 金额: $ 25.5万
• 依托单位: College of Charleston
• 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: 2019-03-08 至 2024-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1929293&HistoricalAwards=false
• 关键词: Collaborative; Research; Investigations; into; microbially

Coral reefs represent a paradox because, despite their immense productivity and biodiversity, they are found in nutrient-poor habitats that are equivalent to "marine deserts." High biodiversity is often associated with a division of resources that allows many types of organisms to coexist with minimal competition. Indeed, unlike many other organisms on coral reefs, sponges are adapted to efficiently remove bacteria, phytoplankton, and dissolved organic matter from seawater by filter-feeding. Sponges are a dominant component of coral reefs worldwide and in the Caribbean, where their biomass exceeds that of reef-building corals. For almost a quarter century, the success of sponges in the Caribbean has been linked to their filter-feeding ability. However, recent work demonstrated that coexisting sponges on Caribbean reefs host unique communities of bacteria that might allow sponges to access multiple pools of nutrients that are not available to other organisms. In this project, the investigators will test the hypothesis that ecologically dominant sponge species in the Caribbean have unique metabolic strategies that are mediated by their associations with microbes that live within the sponge body. This research will combine manipulative field experiments with a novel combination of modern analytical tools to investigate both filter-feeding by sponge hosts and the metabolic pathways of their microbes. This work will advance our understanding of the ecological and evolutionary forces that have helped shape the species present on Caribbean coral reefs. Additionally, this project will support three early-career investigators and provide training opportunities for graduate and undergraduate students at Nova Southeastern University, Appalachian State University, Stony Brook University, and Smithsonian Marine Station. The investigators will also develop innovative outreach programs that expand existing platforms at their institutions to increase public engagement and scientific literacy. Marine sponges have been widely successful in their expansion across ecological niches in the Caribbean, with biomass often exceeding that of reef-building corals and high species diversity. However, whether this success is linked to efficient heterotrophic filter-feeding on organic carbon in the water column or to their evolutionary investment in microbial symbionts is yet to be fully elucidated. Microbial symbionts expand the metabolic capabilities of host sponges, supplementing heterotrophic feeding with inorganic carbon and nitrogen, mediating the assimilation of dissolved organic matter, and facilitating recycling of host-derived nitrogen. Despite these benefits, microbial symbiont communities are widely divergent across coexisting sponge species and there is substantial variation in host reliance on symbiont-derived carbon and nitrogen among host sponges; therefore, these associations likely mediate the ecological diversification of coexisting sponge species. The goal of this project is to test this transformative hypothesis by adopting an integrative approach to assess the individual components of holobiont metabolism (i.e., microbial symbionts and sponge host) in ten of the most common sponge species in the Caribbean. The investigators will isolate autotrophic and heterotrophic metabolic pathways and explore potential links between microbial symbiont community composition and the assimilation of particulate and dissolved organic matter (POM and DOM) from seawater. This project will elucidate whether Caribbean sponge species are on similar or divergent evolutionary trajectories, and will provide information that is critical for our understanding of how conditions in the Caribbean basin have shaped the evolution of benthic organisms.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.

珊瑚礁代表了悖论，因为尽管它们具有巨大的生产力和生物多样性，但它们还是在贫穷的栖息地中发现的，等同于“海洋沙漠”。高生物多样性通常与资源分区有关，该资源使许多类型的生物可以与最小的竞争共存。实际上，与许多其他关于珊瑚礁上的生物不同，海绵可以通过滤滤器有效地清除细菌，浮游植物和溶解有机物。海绵是全球珊瑚礁和加勒比海珊瑚礁的主要组成部分，它们的生物量超过了珊瑚礁建造珊瑚的质量。在将近四分之一世纪的时间里，加勒比海的海绵的成功与它们的过滤器喂养能力有关。但是，最近的工作表明，在加勒比海礁上共存的海绵可以容纳独特的细菌群落，这可能使海绵可以进入多种营养素，而其他生物则无法使用。在该项目中，研究人员将检验以下假设：加勒比海中生态占主导地位的海绵物种具有独特的代谢策略，这些策略是由它们与居住在海绵体内的微生物的关联所介导的。这项研究将将操纵现场实验与现代分析工具的新型组合结合起来，以研究海绵宿主的过滤器喂养和微生物的代谢途径。 这项工作将促进我们对有助于塑造加勒比海珊瑚礁物种的生态和进化力量的理解。此外，该项目将支持三名早期职业研究人员，并为诺瓦东南大学，阿巴拉契亚州立大学，斯托尼·布鲁克大学和史密森尼海洋站的研究生和本科生提供培训机会。研究人员还将开发创新的外展计划，以扩大其机构的现有平台，以提高公众参与和科学素养。海洋海绵在加勒比海地区的生态壁ches方面取得了广泛的成功，生物质通常超过礁石建造珊瑚和高物种多样性的生物量。 但是，这种成功是否与水柱中有机碳上有效的异养过滤器喂养有关，还是与他们在微生物共生体中的进化投资有关。微生物共生体扩展了宿主海绵的代谢能力，补充了无机碳和氮的杂营喂养，介导了溶解有机物的同化，并促进了宿主氮的回收。 尽管有这些好处，微生物共生群落在共存的海绵物种中却有很大不同，并且宿主对宿主海绵中共生体衍生的碳和氮的依赖存在很大差异。因此，这些关联可能介导共存海绵物种的生态多样化。该项目的目的是通过采用综合方法来评估在加勒比海中十种最常见的海绵物种中评估Holobiont代谢（即微生物共生体和海绵宿主）的各个组成部分来检验这种变革性假设的目的。研究人员将分离自养和异养代谢途径，并探索微生物共生群落组成与颗粒和溶解有机物（POM和DOM）的潜在联系。该项目将阐明加勒比海绵物种是否处于相似或不同的进化轨迹上，并将提供对我们了解加勒比海盆地中条件如何塑造底栖生物的演变至关重要的信息。这奖反映了NSF的法定任务，反映了通过使用基础的智力效果和宽阔的评估来评估的支持，并具有评估的支持。

项目成果

Microbial symbionts and ecological divergence of Caribbean sponges: A new perspective on an ancient association

• DOI: 10.1038/s41396-020-0625-3
• 发表时间: 2020-03-20
• 期刊: ISME JOURNAL
• 影响因子: 11
• 作者: Freeman, Christopher J.;Easson, Cole G.;Paul, Valerie J.
• 通讯作者: Paul, Valerie J.