Immunity to Community: Can Quantifying Immune Traits Inform Reef Community Structure?

珊瑚疾病在过去30年中显著增加。气候变化和其他有害环境因素可能是罪魁祸首。不健康的珊瑚礁无法支持鱼类和其他使珊瑚礁成为充满活力和多样化的生态系统的生命。加勒比海的珊瑚礁是疾病的热点，许多珊瑚礁由于疾病的爆发而经历了种群的崩溃。重要的是，珊瑚物种对疾病的易感性各不相同，但这种变化背后的原因尚不清楚。该项目将通过使用几种新方法和实验检查珊瑚免疫力，量化珊瑚对疾病的易感性。将使用在疾病易感性、生长速度、生长形式和繁殖策略方面不同的七种珊瑚。每种珊瑚的免疫反应将通过将珊瑚暴露于细菌免疫刺激剂来测量。白鼠疫是一种影响许多珊瑚物种的流行疾病，研究人员还将珊瑚暴露在活跃的白鼠疫中，并计算疾病传播率，以此来衡量珊瑚对白鼠疫的易感性。每种珊瑚物种的免疫反应和疾病传播数据将用于开发一个预测模型，以确定在气候变化情景下不同珊瑚群落将如何应对疾病威胁。该项目将支持德克萨斯大学阿灵顿分校（西班牙裔服务机构）和维尔京群岛大学（历史上的黑人大学）的研究生以及所有三所大学（莫特海洋实验室）的许多本科生。这项研究将在所有三个机构定期举行的外展活动中得到强调，包括德克萨斯州达拉斯的德克萨斯州地球日，佛罗里达州萨拉索塔的莫特活珊瑚礁展览和水族馆，以及美属维尔京群岛的“珊瑚礁节”和农业博览会。环境变化，如海洋变暖，导致珊瑚疾病发病率上升，在一些地方造成整个区域的珊瑚数量减少。然而，并不是所有的珊瑚物种，甚至物种内的珊瑚种群，都同样受到疾病的影响。有些物种是许多不同类型疾病的宿主，但死亡率有限。其他物种也遭受与疾病相关的严重死亡率。目前尚不清楚物种之间的疾病易感性如何和为什么不同，以及这种不同的易感性对珊瑚礁群落结构和组成的影响。该项目将使用免疫挑战实验，量化珊瑚先天免疫系统的新成分，并结合基于特征的模型的应用，以实现三个目标：1)确定加勒比珊瑚礁上七种常见珊瑚物种的珊瑚免疫特性的可变性；2)确定同一珊瑚物种对白色鼠疫传播的抵抗力的可变性；3)建立一个包含免疫特性的珊瑚群落组合预测模型。珊瑚免疫的量化也将采用独特的方法，例如将全转录组测序与蛋白质活性测定相结合，进行基因到表型分析。数据将被映射到免疫途径上，用于珊瑚物种之间的综合途径评估，这些将作为“特征空间”模型的特征输入。这些特征将在模型中提供连续的数据，这将为每个物种的特征分布创建一个概率密度函数（PDF）。然后，这些pdf文件将用于确定不同疾病暴露情景下物种的概率。模型分析将确定哪些特征会影响群落结构，并描述疾病暴露和免疫反应如何通过空间和时间预测群落组合。完成和应用包含广泛免疫参数的特征基础模型（这些参数都没有应用于珊瑚生态系统中的特征模型）是本项目的一个独特产品。

Coral diseases have increased significantly throughout the past 30 years. Climate change and other detrimental environment factors are likely to blame. Unhealthy coral reefs cannot support the fish and other life that make the reef a vibrant and diverse ecosystem. Corals reefs in the Caribbean Sea are disease hotspots and many reefs have experienced population collapses due to outbreaks of disease. Importantly, coral species vary in their susceptible to disease, but the reasons behind this variation are unknown. This project will quantify coral susceptibility to disease by examining coral immunity using several novel approaches and experiments. Seven species of coral that differ in disease susceptibility, growth rates, growth form and reproductive strategies will be used. Immune responses of each species of coral will be measured by exposing the corals to bacterial immune stimulators. Susceptibility to white plague disease, a prevalent disease affecting many species of corals, will also be measured by exposing the corals to active white plague disease and calculating disease transmission rates. The immune response and disease transmission data for each coral species will be used to develop a predictive model to determine how different coral communities will respond to disease threats under climate change scenarios. This project will support graduate students at University of Texas, Arlington (Hispanic-serving Institution) and University of Virgin Islands (Historically Black University) and many undergraduate students at all three institutions (Mote Marine Laboratory). This research will be highlighted at outreach events at all three institutions which take place regularly and include Earth Day Texas in Dallas, TX, Mote's Living Reef Exhibit and Aquarium in Sarasota, FL and "Reef Fest" and Agricultural fairs in the U.S. Virgin Islands.Environmental changes, such as ocean warming, have led to an increase in the prevalence of coral diseases, causing region-wide population collapses in some locations. However, not all coral species, or even populations within species, are affected by disease equally. Some species are host to many different types of diseases, but have limited mortality. Other species suffer significant disease-related mortality. How and why disease susceptibility differs among species and the effects of this differential susceptibility on reef community structure and composition are currently unknown. This project will use immune-challenge experiments that will quantify novel components of the innate immune system of corals, coupled with the application of a trait-based model, to fulfill three goals: 1) Determine variability of coral immune traits in seven common coral species found on Caribbean reefs, 2) Determine the variability in resistance to white plague disease transmission in the same coral species 3) Develop a predictive model of coral community assemblage that incorporates immune traits. Quantification of coral immunity will also incorporate unique approaches, such as combining full transcriptome sequencing with protein activity assays for a gene-to-phenotype analysis. Data will be mapped onto immune pathways for comprehensive pathway evaluation between coral species and these will serve as trait inputs into a "traitspace" model. These traits will provide continuous data within the model, which will create a probability density function (PDF) for the trait distributions of each species. These PDFs will then be used to determine the probability of species under different disease exposure scenarios. Model analyses will determine which traits influence community structure and characterize how disease exposure and the immune response will predict community assemblages through space and time. The completion and application of a trait-base model that incorporates extensive immunity parameters (none of which have been applied to trait models within coral ecosystems) is a distinct product from this project.