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

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.