CAREER: Understanding the mechanisms that mediate the effects of local ecology on geographic mosaics of host-parasite interactions

环境温度可以通过影响宿主防御和寄生虫生存的有效性来影响宿主-寄生虫关系。实验中升高的温度可以有利于宿主的免疫反应，但也可以达到寄生虫生存和利用宿主的温度上限。温度也可以诱导宿主的热应激，降低其抵抗寄生虫的能力。这一悖论表明，温度偏差对宿主-寄生虫相互作用的影响可能与当地对气候的适应有关，这可以解释宿主免疫反应的地理差异。这项研究的目标是使用协调的实验方法来确定环境因素如何影响巢寄生虫与其箱巢宿主、美国东部蓝知更鸟（Sialia sialis）之间的相互作用。首先，该研究将研究当地环境因素，巢寄生虫因素和宿主筑巢成功与公开的环境数据之间的关系，以及通过最近建立的公民科学项目收集的宿主和寄生虫数据：“巢寄生虫社区科学项目”。接下来，该研究将使用协调实验来确定温度如何影响宿主免疫发育和寄生虫在蓝鸟范围内的生存。这项研究将通过学习和参与科学研究的整个过程，与服务不足的磁铁学校的K-12教师和Nest Parasite社区科学项目的公众建立持久的联系。与自然的关系不仅可以促进心理健康，而且以社区为基础的科学项目可以帮助教育公众环境问题，使他们在社会中做出明智的决定。拟议的研究通过使用协调的实验方法来确定环境因素如何影响宿主-寄生虫的地理马赛克跨越环境梯度的相互作用。中心假设是，温度的变化是一个重要的驱动程序的主机-寄生虫马赛克，其结果是介导的温度对寄生虫健身和早期生命的主机免疫抵抗力的差异影响整个主机范围。该研究将通过对当地环境因素、巢寄生虫类群的存在和丰度以及宿主范围内的宿主筑巢成功率进行空间和时间建模来验证这一假设。该研究还将确定在发育的不同阶段温度的实验性变化是否会影响早期生命对寄生虫的免疫结果。具体而言，温度（更热，更冷，没有变化）将在不同的主机发育阶段，主机和寄生虫相互作用之前和期间进行操作，并将表征免疫机制和巢寄生虫因子的变化。跨多个尺度的协调努力是迫切需要的因果关系，以确定创建和维持宿主寄生虫的地理镶嵌在环境梯度的基本机制。要同时在多个地方，需要与多个地点的研究科学家或社区科学家合作。通过创造性地将公众、教授、K-12、本科生和研究生联系起来，拟议的研究有望通过改变我们对因果环境因素和促进宿主-该奖项反映了NSF的法定使命，并被认为是值得通过使用基金会的学术价值和更广泛的影响评审标准。

Environmental temperatures can influence host-parasite relationships by affecting the effectiveness of host defenses and parasite survival. Experimentally elevated temperatures can favor the host’s immune response but can be at the upper thermal limits for which parasites survive and exploit the host. Temperatures can alternatively induce heat stress for hosts, reducing their capacity to resist parasites. This paradox suggests that the effect of temperature deviations on host-parasite interactions might be related to local adaptation to climate, which could explain geographical variation in the hosts’ immune response. The goal of this research is to use coordinated, experimental approaches to determine how environmental factors affect interactions between nest parasites and their box-nesting host, eastern bluebirds (Sialia sialis) across the eastern US. First, the research will examine the relationship among local environmental factors, nest parasite factors, and host nesting success with publicly available environmental data, as well as host and parasite data collected through a recently established, citizen science project: “Nest Parasite Community Science Project”. Next, the research will use coordinated experiments to determine how temperature affects host immune development and parasite survival across the bluebird’s range. The research will build lasting connections with K-12 teachers at underserved magnet schools and the public from the Nest Parasite Community Science Project through learning and being involved in the entire process of a scientific study. Not only can a relationship with nature promote mental health, but community-based science projects can help educate the public on environmental issues so that they make informed decisions in society.The proposed research examines host-parasite geographic mosaics by using coordinated, experimental approaches to determine how environmental factors affect host-parasite interactions across an environmental gradient. The central hypothesis is that variation in temperature is an important driver of host-parasite mosaics, and the outcome of which is mediated by the differential effects of temperature on parasite fitness and early-life host immunological resistance across the host range. The research will test this hypothesis by spatially and temporally modeling local environmental factors, presence and abundance of nest parasite taxa, and host nesting success across the host’s range. The research will also determine whether experimental changes in temperature during the different stages of development influences outcomes of early-life immunity against parasites. Specifically, temperature (hotter, colder, no change) will be manipulated at different host developmental stages, before and while host and parasites are interacting, and changes in immune mechanisms and nest parasite factors will be characterized. Coordinated efforts across multiple scales are critically needed to causally determine the underlying mechanisms that create and maintain host-parasite geographic mosaics across an environmental gradient. To be in multiple places at the same time requires collaborations with research scientists or community-based scientists across a multitude of locations. By creatively linking the general public, professors, and K-12, undergraduate, and graduate students, the proposed research promises to provide novel insights into the emerging field of eco-evo dynamics through transforming our understanding of the causal environmental factors and mechanisms that facilitate host-parasite geographic mosaics.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.