CAREER: Unraveling post-invasion dynamics of the amphibian-killing fungus via rapid genetic diversity assessments of both hosts and pathogens

在野生动物中，真菌病（由真菌引起的疾病）的突出例子包括白鼻综合征和最近传播和出现的蛇真菌病，但没有其他真菌病原体对野生动物的破坏性比两栖动物壶菌（壶菌属）更大。壶菌基本上在环境中无处不在，但对它们的研究相对不足。两栖壶类继续导致全球数量下降和物种灭绝。不幸的是，最严重的两栖动物减少发生在新热带森林，也受到森林砍伐的威胁。对于热带两栖动物来说，疾病的威胁加上栖息地的丧失，需要在种群规模上快速测量宿主多样性，以揭示复杂的疾病动态。疾病动力学的研究可以受益于可在现场实时应用的遗传方法的发展和使用。通过利用新兴的便携式技术来测量遗传多样性，该项目将收集宿主和病原体的数据，以测试关于它们相互作用特异性的假设，确定哪些宿主驱动传播或充当宿主，并为两栖动物保护做出贡献。该项目的研究和教育目标将在西班牙裔服务机构实施，并由第一代墨西哥裔美国首席研究员（PI）领导，因此，将增加各级代表性不足群体对STEM的参与。此外，该项目将培训下一代学生和国际生物学家应用新兴的遗传方法来解决疾病生态学中的共同挑战，这些方法可以外推到其他不同宿主驱动病原体传播的系统中。该项目的总体目标是通过确定哪些宿主驱动了从兽疫到地方性兽疫病原体的转变，阐明赤道森林及其未充分研究的冠层的真菌病原体多样性和入侵后病原体动态。本研究的目的是：1)使用便携式定量PCR仪器进行实时菌株检测，并使用便携式纳米孔测序仪进行DNA测序，以揭示赤道样带的病原体多样性和地理分布；2)在高度多样化的组合中分析两栖动物的遗传身份，以便对病原体/菌株的流行进行宿主特异性估计；3)使用共同进化分析来测试宿主多样性对病原体入侵的影响。PI在实现这些研究目标方面具有独特的优势，同时为本科和研究生阶段STEM中代表性不足的学生提供体验式学习机会。本项目由美国国家科学基金会环境生物学部系统学与生物多样性研究小组和进化过程研究小组共同资助。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

In wildlife, prominent examples of mycoses (diseases caused by fungi) include white-nose syndrome and the recent spread and emergence of snake fungal disease, but no other fungal pathogens have been more destructive to wildlife than the amphibian chytrids (genus Batrachochytrium). Chytrids are essentially ubiquitous in the environment, yet they are relatively understudied. Amphibian chytrids continue to cause population declines and species extinctions globally. Unfortunately, the most severe amphibian declines have occurred in Neotropical forests, which are also threatened by deforestation. For tropical amphibians, the threat of disease, coupled with habitat loss, requires rapid measurements of host diversity at the population scale to unravel complex disease dynamics. Studies of disease dynamics can benefit from the development and use of genetic methods that can be applied in real-time and in the field. By leveraging emerging portable technology to measure genetic diversity, this project will gather data for both hosts and pathogens to test hypotheses regarding the specificity of their interactions, determine which hosts drive spread or act as reservoirs, and contribute to amphibian conservation. The research and educational goals of the project will be implemented at a Hispanic-Serving Institution and led by a first-generation, Mexican-American Principal Investigator (PI), and thus, will increase the participation of underrepresented groups in STEM at all levels. Additionally, the project will serve to train the next generation of students and international biologists in the application of emerging genetic methodologies to address common challenges in disease ecology, which can be extrapolated to other systems where diverse hosts drive pathogen spread.The overarching goal of this project is to elucidate fungal pathogen diversity and post-invasion pathogen dynamics in equatorial forests and their understudied canopies by identifying which hosts have driven the transition from an epizootic to an enzootic pathogen. The aims of this research are to: 1) perform real-time strain detection using portable quantitative PCR instruments and DNA sequencing using portable nanopore sequencers to reveal pathogen diversity and geographic distribution along an equatorial transect, 2) parse amphibian genetic identity in a hyper-diverse assemblage to allow host-specific estimates of pathogen/strain prevalence, and 3) use cophylogenetic analyses to test for the influence of host diversity on pathogen invasions. The PI is uniquely positioned to achieve these research goals while providing experiential learning opportunities to underrepresented students in STEM at the undergraduate and graduate level.This project is being jointly funded by the Systematics and Biodiversity Cluster and the Evolutionary Processes Cluster in the Division of Environmental Biology at the National Science Foundation.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.