Exploring the role of boundary layer microbial remineralization in flavivirus-host dynamics

面对不断变化的海洋条件，海洋疾病对海参等无脊椎动物构成相当大的风险。虽然许多无脊椎动物疾病是由病原体驱动的，但动物生物学和环境条件之间的相互作用往往介导了病原体-宿主关系的结果。海参是生态和经济上重要的动物，分布在广泛的海洋栖息地。该项目旨在破译海参生物学、环境条件和一种在典型条件下看似无害的新发现病毒之间的相互作用如何导致美国西海岸巨型太平洋海参的致命疾病。这项研究包括对阿拉斯加东南部、华盛顿和加利福尼亚沿海地区的调查，以及操纵海水氧浓度、温度和模拟微藻华的实验室实验。该项目有社区科学家、渔民、高中生和土著群体参与，并支持培训一名研究生和几名本科生。计划举办一次讲习班，汇集海洋生态学、疾病和兽医学科的科学家，以编写一本关于海洋疾病调查最佳做法的手册。宏基因组和群落水平的测序工作揭示了与基本正常的海洋无脊椎动物相关的病毒的惊人多样性。绝大多数检测到的病毒在典型条件下可能代表无症状感染，但在不断变化的环境条件下可能在宿主中产生病理。本项目研究了该研究小组最近在加利福尼亚巨海参Apostichopus californicus中发现的一组包膜阳性单链RNA病毒（黄病毒）的生态学，解决了三个假设：1)水生昆虫的黄病毒（aiFVs）在典型条件下不会引起严重病理；2)缺氧胁迫下aifv增殖并产生临床病理和大体病理；3)初级产量的周期性增加和平均温度的漂移导致aiFV增殖，从而加剧了海枯病的发病过程。该研究包括通过扩增子测序及其在人群内和人群之间的流行程度对aiFV多样性进行限制性调查，开发基于抗体的aiFV检测方法，并根据宿主转录和兽医病理检查aiFV行为。本研究包括实地调查和室内操作实验。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Marine diseases pose considerable risks to invertebrates, such as sea cucumbers, in the face of changing ocean conditions. While many invertebrate diseases are driven by pathogens, the interplay between animal biology and environmental conditions often mediates the outcome of the pathogen-host relationship. Sea cucumbers are ecologically and economically important animals that occur in a wide range of marine habitats. This project aims to decipher how the interaction between the biology of sea cucumbers, environmental conditions, and a newly-discovered type of virus, seemingly innocuous under typical conditions, may lead to lethal disease in giant Pacific sea cucumbers in the U.S. West Coast. The study includes surveys in coastal regions in southeast Alaska, Washington, and California as well as laboratory experiments manipulating seawater oxygen concentrations, temperature, and simulated microalgal blooms. The project engages community scientists, fishers, high school students, and indigenous groups, and supports training of one graduate and several undergraduate students. A workshop that brings together scientists across marine ecology, disease, and veterinary disciplines is planned to prepare a handbook of best practices in marine disease investigation. Metagenomic and community-level sequencing efforts have revealed an astonishing diversity of viruses associated with grossly normal marine invertebrates. The vast majority of detected viruses likely represents asymptomatic infections under typical conditions but may generate pathology in hosts under changing environmental conditions. This project investigates the ecology of a group of enveloped positive sense single-stranded RNA viruses (flaviviruses) that this research team has recently discovered in the giant California sea cucumber Apostichopus californicus by addressing three hypotheses: 1) Aquatic insect-only Flaviviruses (aiFVs) do not cause gross pathology under typical conditions; 2) aiFVs proliferate and generate clinical and gross pathology under suboxic stress; and 3) Periodic increases in primary production and mean temperature excursions cause aiFV proliferation and subsequently exacerbate holothurian disease process. The study comprises a restricted survey of aiFV diversity via amplicon sequencing and their prevalence within and between populations, development of an antibody-based approach for aiFV detection, and examination of aiFV behavior in concert with host transcription and veterinary pathology. The study includes field surveys and in laboratory manipulative experiments.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.