NSF Postdoctoral Fellowship in Biology FY 2017: Historical pathogen dynamics of an epidemic invasion

Jenkinson Thomas S, Ann Arbor MI

Investigators

Abstract

This action funds an NSF Postdoctoral Research Fellowship in Biology for FY 2017, Research Using Biological Collections. The fellowship supports research and training of the fellow that will utilize biological collections in innovative ways. Newly invading diseases are a major threat to global biodiversity, crop security, and human health. Understanding the genetics of past epidemics can shed light on how pathogens adapt as they colonize new hosts and habitats. Natural history collections present a valuable opportunity to learn about epidemics over time because pathogens are preserved along with animal specimens as they are collected. The idea of unlocking pathogen history using zoological collections is not new, but its execution has remained a challenge until recent advances in studying trace amounts of historical DNA. This research focuses on an invasion of the amphibian-killing chytrid disease into the Atlantic Forest of southern Brazil. This project will provide genetic insights into how invasive diseases establish and move across a novel landscape. A detailed understanding of how spreading diseases evolve will be critical to controlling future outbreaks, especially as pathogens are increasingly introduced to new habitats by human activity. This project will recruit undergraduates from underrepresented groups in biology to participate in molecular biology research, and will translate project insights into educational modules for use by the K-12 teaching community. This research seeks to understand the consequences of human-mediated strain introduction into an endemic pathogen system. Sometime in the last century, a global pandemic strain of the amphibian-killing chytrid was introduced to southern Brazil, where prior studies suggest it has competitively excluded less virulent, locally endemic strains of the disease. The fellow is adapting techniques developed for the isolation and genomic sequencing of single cells to target pathogen colonies in museum-preserved amphibian tissue. Historical specimens from the University of Campinas, the University of São Paulo, and the University of California, Berkeley are being studied for this project. Using a combination of targeted amplicon and whole genome sequencing, this project aims to: i) test alternative demographic scenarios of pathogen strain invasion; ii) identify signatures of natural selection accumulated over a century of range expansion in these pathogen lineages. Results from these studies will be published in peer-reviewed journals and presented at scientific meetings.