Collaborative Research: Using Transcriptomics to Understand Mechanisms of Stress Response and Toxin Production in Pathogenic and Toxigenic Microbes in Tropical Marine Waters

在这个项目中，来自夏威夷大学马诺阿分校、斯坦福大学和罗格斯大学的跨学科研究小组将研究夏威夷沿海沃茨中的冈比亚盘菌、金黄色葡萄球菌和肠球菌的转录组--这些产毒物种对人类造成重大健康危害。他们的目标是阐明与冈比亚盘菌毒素产生和细菌病原体S.金黄色葡萄球菌和粪便指示剂肠球菌。由于生物体的转录组反映了在任何给定时间积极表达的基因，因此本研究通过阐明靶生物体中信使RNA的表达水平，应该为毒素产生、应激反应和/或随后的细菌灭活机制提供有价值的见解。研究计划将围绕四个工作假设：H1：由甘比盘菌生产雪卡毒素反映了受温度，光照和生长阶段影响的培养物的生理条件。H2：毒素（+）和毒素（-）文化的高通量转录组分析将允许参与雪卡毒素生产的基因的鉴定和了解有利于这一功能的光和营养条件。H3：而E. faecalis在海水中暴露于阳光下易受间接光灭活，S.而aureus却没有。这可能是由于细胞内存在类胡萝卜素色素，能够淬灭活性氧。H4：E. faecalis和S.金黄色葡萄球菌通过上调编码蛋白质的基因来修复细胞损伤和减轻氧化应激，从而对清澈海水中的光应激作出反应;这种“应激体”将随着暴露于光应激的增加而改变，揭示了修复不再可能的应激。更广泛的影响：本研究中收集的信息预计将大大有助于推进休闲用水和海鲜消费方面的风险管理领域，超越对经验相关性的依赖，并制定基于对这些生物体构成的威胁的机械理解的政策。对人类健康。

In this project an interdisciplinary research team from the University of Hawaii at Manoa, Stanford University, and Rutgers University will study the transcriptomes of Gambierdiscus, Staphylococcus aureus, and Enterococcus in Hawaiian coastal waters - toxin-producing species that pose significant health hazards to humans. Their goal is to elucidate the mechanisms associated with toxin production by Gambierdiscus and inactivation by sunlight of the bacterial pathogen, S. aureus, and the fecal indicator, Enterococcus. Because the transcriptome of an organism reflects the genes that are actively being expressed at any given time, this study, by elucidating levels of messenger RNA expression in the target organisms, should provide valuable insights into the mechanisms responsible for toxin production, responses to stress and/or subsequent bacterial inactivation. The research program will be organized around four working hypotheses: H1: Production of ciguatoxin by Gambierdiscus reflects the physiological condition of the culture as influenced by temperature, irradiance, and growth phase. H2: High throughput transcriptome analysis from toxin (+) and toxin (-) cultures will allow the identification of genes involved in ciguatoxin production and understanding of the light and nutrient conditions that favor this function. H3: Whereas E. faecalis is susceptible to indirect photoinactivation under exposure to sunlight in seawater, S. aureus is not. This is likely due to the presence of carotenoid pigments within the cells, which are able to quench reactive oxygen species. H4: E. faecalis and S. aureus respond to photo-stress in clear seawater by up-regulating genes that encode for proteins to repair cellular damage and mitigate oxidative stress; this "stressome" will change with increasing exposure to photostress, revealing the stress at which repair is no longer possible. Broader Impacts: The information that will be gathered in this study is expected to contribute significantly to advancing the field of risk management with respect to recreational water use and seafood consumption beyond reliance on empirical correlations and towards policies that are based on a mechanistic understanding of the threats these organisms pose to human health.