Collaborative Research: Eukaryotic virus-host interaction and evolution in Saccharomyces yeasts
No virus can infect all host species; therefore virus host range is limited. Sometimes, a change in even one cellular component may turn a host to a resistant host, or a resistant host into a host for the virus. This project will study brewer's/baker's yeast (Saccharomyces cerevisiae) to understand how the presence of a virus can select for host-specific changes that alter the replication of viruses, and how viruses can adapt to infect new hosts. The familiarity and public interest in brewer's/baker's yeast will facilitate the outreach to the public, and experimental evolution curriculum will be developed for high schools using yeasts. The goal of this project is to identify adaptive changes that occur within S. cerevisiae in response to viral parasitism and the evolutionary response of viruses to changing host environments. Persistence of viruses within yeasts drives the evolution of both host and virus as cellular machinery adapts to abrogate virus replication and viruses evolve to ensure their persistence. Saccharomyces yeasts that are infected with different types of viruses will be evolved in the laboratory over hundreds of generations to observe the evolutionary response to viral parasitism in real-time. Next generation sequencing techniques will be used to identify adaptive genetic changes in either the host or virus that are important for persistent viral replication and/or antiviral defense. The genetic tools available for S. cerevisiae will allow the manipulation of both host and virus to identify the consequences of adaptive changes on virus persistence. This work will build on previous observations that have identified species-specific changes in host genes that can affect the replication of viruses within Saccharomyces yeasts. The expected outcomes of this research are a better understanding of the dynamic interplay between virus and host over multiple generations and the identification of genes and cellular processes that govern viral persistence within S. cerevisiae. Due to the common ancestry and conserved cellular mechanisms of eukaryotic organisms, these findings could potentially be applicable to virus-host interactions of higher eukaryotes. 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.