Microbial ecology of sea star wasting disease

海星消耗性疾病的微生物生态学

• 批准号: 1537111
• 负责人: Ian Hewson
• 金额: $ 56.46万
• 依托单位: Cornell University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-08-15 至 2020-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1537111&HistoricalAwards=false
• 关键词: Microbial; ecology; sea; star; wasting

Beginning in June 2013 and continuing to present (May 2015), over 20 species of sea stars (Asteroidea, Echinodermata) have been affected by sea star wasting disease (SSWD), affecting populations from central Alaska to Baja California. The disease has lead to greatly reduced abundance or disappearance of these keystone predators, which may result in profound alteration to benthic community structure. Recent work has identified the sea star associated densovirus (SSaDV) as the most likely causative agent of the disease. SSaDV is related to densoviruses inhabiting other echinoderms worldwide, and has been present in West Coast asteroid populations for at least 72 years. Hence, there remain significant knowledge gaps in our understanding of how SSaDV actually elicits SSWD symptoms, especially how the echinoderm host, densovirus and microbiome constituents interact. This project will address three major questions: 1) does viral infection change the composition of the sea star microbiome?, 2) what is the variation of viral genomes and their associated virulence?, and 3) does larval dispersal spread the disease between habitats? This project will address these hypotheses through time-course measurements of host, pathogen and associated microorganisms, genome-genome comparisons between historical and contemporary viral strains, and through experiments targeting larvae and juvenile asteroids in aquaria and in nature. This work will support training of a graduate student (recruitment targeting an under-represented minority) and several undergraduates in biological oceanographic and disease ecology techniques. Information will be disseminated through public outreach activities at two high-profile Pacific coast public aquariums (the Seattle and Vancouver Aquariums), through a website dedicated to the project, and through public talks and media exposure. This project will address three fundamental questions relating to Sea Star Wasting Disease (SSWD): 1) How does SSaDV causes SSWD symptoms and how does the disease progress from primary infection through animal mortality; 2) How do current genotypes of SSaDV vary from those present historically, and is virulence related to genome polymorphisms; and 3) Are larvae and juvenile asteroids differentially affected by SSaDV, and are broadcast-spawned bipinarria a viable mechanism for SSaDV dispersal between distant habitats. The first question will be addressed by experimental inoculation of naïve sea stars with SSaDV, then time-course monitoring of host transcription (i.e. transcriptomics via RNAseq), microbiome composition via 16S rRNA sequencing and quantitative PCR, and viral load and prevalence using quantitatice PCR. The second question will be addressed by amplifying the entire genome of SSaDV and related densoviruses, then perform genome-genome comparisons to identify polymorphic DNA in key protein-encoding regions. The third question will be addressed by collecting bipinarria from plankton at field locations adjacent to spawning asteroid populations, and by performing time-course observations of captive juvenile sea stars and monitoring their bacterial and viral loads using quantitative PCR. This work will be performed primarily in the Salish Sea region, with SSaDV - naïve asteroids collected from Alaskan waters.

从2013年6月开始并继续存在（2015年5月），超过20种海星（小行星，echinodermata）受到海星浪费疾病（SSWD）的影响，影响了从阿拉斯加中部到加利福尼亚州巴哈的人口。该疾病导致这些基石捕食者的抽象或消失大大减少了，这可能会导致对底栖群落结构的深刻改变。最近的工作已经确定海星相关的致电病毒（SSADV）是该疾病中最有可能的灾难性药物。 SSADV与全球遗传其他棘皮动物的致密病毒有关，并且至少在西海岸的小行星种群中已经存在了72年。因此，我们对SSADV如何实际echinoderms SSWD症状的理解仍然存在很大的知识差距，尤其是棘皮动物宿主，致密病毒和微生物组成分如何相互作用。该项目将解决三个主要问题：1）病毒感染会改变海星微生物组的组成吗？，2）病毒基因组及其相关病毒的变化是什么？和3）幼虫疾病在栖息地之间会传播疾病吗？该项目将通过对宿主，病原体和相关微生物的时间顺序测量，历史和当代病毒菌株之间的基因组基因组进行比较以及针对水族箱中幼虫和少年小行星的实验来解决这些假设。这项工作将支持对研究生的培训（针对代表性不足的少数群体的招聘）和生物海洋学和疾病生态技术的几名本科生。信息将通过两个备受瞩目的太平洋海岸公共水族馆（西雅图和温哥华水族馆），通过专门针对该项目的网站，以及公众的谈判和媒体曝光来传播信息。该项目将解决与海星浪费疾病有关的三个基本问题（SSWD）：1）SSADV如何导致SSWD症状以及该疾病从初次感染到动物死亡率如何发展； 2）SSADV的当前基因型与历史上的基因型有何不同，并且与基因组多态性有关的病毒；和3）是幼虫和少年小行星受SSADV差异影响，并且是广播产生的双纳米，这是分散栖息地之间SSADV扩散的可行机制。第一个问题将通过用SSADV实验接种幼稚的海星，然后对宿主转录（即通过RNASEQ进行转录组学），通过16S rRNA测序和定量PCR进行微生物组组成的时间顺序监测，以及使用定量PCR的病毒载荷和病毒载荷和患病率。第二个问题将通过扩增SSADV和相关致密病毒的整个基因组，然后进行基因组基因组比较以鉴定关键蛋白质编码区域中的多态性DNA。第三个问题将通过在与产卵小行星种群相邻的浮游生物中收集二比尼里亚，并通过定量PCR对圈养少年海星进行时间课程观察并监测其细菌和病毒载荷。这项工作将主要在萨利什海地区进行，SSADV - 幼稚的小行星从阿拉斯加水域收集。