Testing Mechanistic Models to Explain How Variation in Host Susceptibility Arises and Why It Shifts Across Thermal Gradients.

测试机械模型来解释宿主敏感性的变化是如何产生的以及为什么它会随着热梯度的变化而变化。

• 批准号: 2309480
• 负责人: Nathan Wolf
• 金额: $ 299.24万
• 依托单位: Alaska Pacific University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-08-15 至 2028-07-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2309480&HistoricalAwards=false
• 关键词: Testing; Mechanistic; Models; Explain; How

Shifting environmental conditions resulting from climate change have the potential to alter established ecological interactions, including the dynamics between pathogens and hosts. As a result, developing a thorough understanding of both the mechanisms that drive host-pathogen dynamics and the influence of environmental conditions on these mechanisms is of paramount importance to predicting and preparing for the effects of future environmental change. This work tests novel hypotheses about the general mechanisms by which temperature influences pathogen susceptibility in Pacific herring, an ecologically and economically important marine forage fish. Hypotheses are being tested by fitting mathematical models to laboratory and field-collected data that evaluate the responses of herring and cold- and warm-water adapted pathogens across thermal gradients. The foundational information resulting from this work increases predictive capacities to assess the effects of a changing climate on the long-term stability of host-pathogen interactions and to build links between fundamental evolutionary processes and disease ecology. Further, results inform fisheries managers about impacts of increased water temperatures on herring epizootics; thereby allowing for a more nuanced use of disease information in herring stock assessment models and contributing to sustainable aquatic resource management. Beyond the study’s relevance to fisheries, the broader impacts focus on creating and evaluating multi-lingual outreach materials that educate high school and university students on how climate and disease interact to affect agricultural and wildlife species. The investigators are also developing a simple, interactive web application for managers to explore the model.The distribution of susceptibility in a host population determines short- and long-term epidemic characteristics. However, little is known about the mechanisms that generate variation in susceptibility, and current theory assumes that the distribution of susceptibility is fixed across environmental conditions. Our capacity to understand and predict epidemic outcomes under climate change is therefore limited. The central hypothesis of this proposal seeks to test this assumption by positing that the variation in pathogen susceptibility arises as a stochastic process defined by the relative performance of host and pathogen traits under a given temperature condition. Alternatively, variation in susceptibility may be explained by genetic variation in the thermal reaction norms of host susceptibility. These hypotheses are tested using warm- and cold-water adapted pathogens in Pacific herring and will involve the use of mathematical models to link the within-host infection dynamics to among-host transmission dynamics. Developed theory is being further scrutinized against experimental data obtained from laboratory and field epizootic experiments. By rigorously testing theory against collected data, this project provides insights into general mechanisms that generate variation in disease susceptibility and quantifies the roles that thermal gradients play in shaping susceptibility distributions. As a result, this project has the potential to provide new approaches to assess the consequences of a changing climate on the long-term stability of host-pathogen interactions. Furthermore, by describing the interplay between the distribution of susceptibility and temperature, this project identifies basic mechanistic processes that could be the foci of disease mitigation under climate change.This Ecology and Evolution of Infectious Diseases project is jointly funded by the Biological Oceanography Program and the Established Program to Stimulate Competitive Research (EPSCoR).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.

由于气候变化而导致的环境条件的转移有可能改变已建立的生态相互作用，包括病原体和宿主之间的动态。结果，对驱动宿主病原动力学的机制以及环境条件对这些机制的影响进行彻底了解对于预测和准备未来环境变化的影响至关重要。这项工作检验了有关温度在生态和经济上重要的海洋饲料鱼类中影响病原体易感性的一般机制的新颖假设。通过将数学模型与实验室和现场收集的数据拟合，从而评估了鲱鱼和冷水和热水适应于热梯度的病原体的反应，从而测试了假设。这项工作产生的基本信息增加了预测能力，以评估气候变化对宿主病原体相互作用的长期稳定性的影响，并在基本进化过程与疾病生态学之间建立联系。此外，结果将水温升高对鲱鱼epizootics的影响告知渔业经理；从而允许在鲱鱼库存评估模型中更细微的使用疾病信息，并为可持续的水生资源管理做出贡献。除研究与渔业的相关性外，更广泛的影响着重于创建和评估多种语言外展材料，教育高中和大学生关于气候和疾病如何相互作用以影响农业和野生动植物的物种。研究人员还正在开发一个简单的交互式Web应用程序，以供经理探索该模型。宿主人群中的易感性分布决定了短期和长期的流行特征。但是，对产生易感性变化的机制知之甚少，当前理论假设易感性的分布是在环境条件下固定的。因此，我们理解和预测气候变化下的流行结果的能力受到限制。该提案的中心假设旨在通过理解病原体易感性的变化作为由宿主和病原体特征在给定温度条件下的相对性能定义的随机过程来测试这一假设。或者，易感性的差异可以通过宿主易感性的热反应规范的遗传变异来解释。这些假设使用太平洋鲱鱼中的温水和冷水适应的病原体进行了测试，并将涉及使用数学模型将宿主内感染动力学与宿主传播动态之间的联系。开发的理论正在进一步审查从实验室和现场epizootic实验获得的实验数据。通过严格测试收集数据的理论，该项目提供了对疾病敏感性变化的一般机制的见解，并量化了热梯度在塑造敏感性分布中起作用的作用。结果，该项目有可能提供新的方法来评估气候变化对宿主 - 病原体相互作用的长期稳定性的后果。此外，通过描述易感性和温度的分布之间的相互作用，该项目确定了在气候变化下可能是缓解疾病的焦点的基本机制过程。此类生态和感染性疾病项目的进化项目由生物学海洋学计划和既定的计划（通过启发竞争性研究）共同资助。基金会的智力优点和更广泛的影响审查标准。