Collaborative Research: LTREB Renewal: Long-Term Dynamics of Amphibian Populations Following Disease-Driven Declines

合作研究：LTREB 更新：疾病驱动的衰退后两栖动物种群的长期动态

• 批准号: 2133400
• 负责人: Erica Rosenblum
• 金额: $ 17.85万
• 依托单位: University of California-Berkeley
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-05-01 至 2027-04-30
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2133400&HistoricalAwards=false
• 关键词: Collaborative; Research; LTREB; Renewal; Long

This project will examine the processes of invasion of a novel pathogen into a population for the case of a fungal pathogen that causes the disease chytridiomycosis in frogs and salamanders. Outbreaks of emerging infectious diseases are increasingly recognized as major threats, not just to human populations but also to wildlife, and they increasingly threaten global biodiversity. The initial invasion of a novel pathogen into a susceptible host population can cause a disease outbreak resulting in high levels of mortality and declines in population size. When this happens, natural selection can occur for both the host and pathogen populations resulting in evolutionary changes in the host's susceptibility and tolerance to infection by the pathogen and the pathogen's ability to damage the host (virulence). These changes can in turn determine whether the host population can persist and recover from the disease. Understanding these evolutionary processes is crucial in development of conservation strategies for threatened species. Chytridiomycosis has had catastrophic effects on amphibians worldwide, and has been linked to numerous species extinctions in recent decades and many more species at risk. The researchers will investigate the patterns of evolutionary change in both the pathogen and the host (mountain yellow-legged frogs), following the invasion of the disease into hundreds of high elevation lakes in the California Sierra Nevada. This project will contribute to the understanding of the role of infectious diseases, such as chytridiomycosis, as agents of evolutionary change in natural populations. It will provide critical information to state and federal agencies, facilitating endangered species recovery and will train and educate undergraduates, graduate students, and the general public.This research builds on data from a long-term study of the population dynamics of mountain yellow-legged frogs (Rana sierrae and Rana muscosa) in the complex landscape of the California Sierra Nevada, and the affects of Batrachochytrium dendrobatidis (Bd) as it has invaded and spread through hundreds of frog populations. In most cases, invasion of Bd results in outbreaks of the disease chytridiomycosis, rapid frog population declines, and local extinctions. In some cases, long-term persistence of frog populations occurs with Bd in an enzootic state in which the impact of the pathogen is greatly reduced. The research will extend and leverage 25 years of host population and disease data and archived genetic samples from R. sierrae/R. muscosa and Bd. These resources will provide insight into how populations of both host and pathogen change during the transition from pre-pathogen arrival, to disease outbreak, to enzootic disease, to potential recovery of the pre-disease host population abundances. This dataset will be used to investigate the genetic basis for differences in host resistance/tolerance and pathogen virulence. Cutting-edge genomic analysis of existing frog and fungal samples will complement laboratory experiments on Bd virulence and frog susceptibility using Bd cultures and frog mucosal samples from wild host populations. Continued surveys of wild host populations will identify new disease outbreaks and describe the transition from initial outbreak to persistent enzootic state.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.

该项目将研究一种新型病原体侵入种群的过程，以引起青蛙和蝾螈壶菌病的真菌病原体为例。人们越来越认识到新出现的传染病的爆发不仅对人类而且对野生动物构成重大威胁，并且日益威胁着全球生物多样性。新型病原体最初入侵易感宿主群体可能会导致疾病爆发，导致高死亡率和种群规模下降。当这种情况发生时，宿主和病原体种群都会发生自然选择，导致宿主对病原体感染的易感性和耐受性以及病原体损害宿主的能力（毒力）发生进化变化。这些变化反过来可以决定宿主群体是否能够持续患病并从疾病中恢复。了解这些进化过程对于制定受威胁物种的保护策略至关重要。壶菌病对全世界的两栖动物造成了灾难性影响，并与近几十年来许多物种的灭绝以及更多物种面临危险有关。研究人员将研究该疾病入侵加利福尼亚州内华达山脉数百个高海拔湖泊后，病原体和宿主（山黄腿蛙）的进化变化模式。该项目将有助于了解壶菌病等传染病作为自然种群进化变化的推动者的作用。它将向州和联邦机构提供关键信息，促进濒危物种的恢复，并将培训和教育本科生、研究生和公众。这项研究建立在对山地黄腿种群动态的长期研究的数据基础上加利福尼亚内华达山脉复杂景观中的青蛙（山蛙和林蛙），以及 Batrachochytrium dendrobatidis (Bd) 入侵并通过数百只青蛙传播的影响人口。在大多数情况下，Bd 的入侵会导致壶菌病的爆发、青蛙数量的迅速下降和局部灭绝。在某些情况下，青蛙种群长期存在，Bd 处于地方性动物流行状态，其中病原体的影响大大减少。该研究将扩展和利用 25 年的宿主种群和疾病数据以及来自 R. serrae/R. 的存档遗传样本。穆斯科萨和 Bd。这些资源将深入了解宿主和病原体的种群在从病原体到达前到疾病爆发、到地方性动物疾病、到疾病前宿主种群丰度的潜在恢复的过渡过程中如何变化。该数据集将用于研究宿主抗性/耐受性和病原体毒力差异的遗传基础。对现有青蛙和真菌样本的尖端基因组分析将补充使用 Bd 培养物和来自野生宿主群体的青蛙粘膜样本进行 Bd 毒力和青蛙敏感性的实验室实验。对野生宿主种群的持续调查将确定新的疾病暴发，并描述从最初暴发到持续流行状态的转变。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。