NSF Postdoctoral Fellowship in Biology FY 2019: The impact of transmission mode on symbiont evolution

Hoang, Kim, Atlanta GA

Investigators

Abstract

This action funds an NSF Postdoctoral Research Fellowship in Biology for FY 2019, Broadening Participation of Groups Underrepresented in Biology. The fellowship supports a research and training plan for the Fellow that will increase the participation of groups underrepresented in biology. Host-microbe associations are common in nature and the goal of the project is to understand how microbes evolve to benefit their hosts. For a beneficial microbe (called a symbiont) to persist in the host population for many generations, it has to be passed on from parent to offspring (called vertical transmission), or taken up from the environment between unrelated hosts (called horizontal transmission). Theory suggests that transmission mode has a critical role in how symbionts will evolve. However, there has been little research to test this idea. This project will determine how transmission mode affects symbiont evolution using an experimental system. Because microbes have considerable influence on their hosts, understanding how symbionts evolve will also provide insight into the evolution of hosts themselves. Components of this research will be implemented at the middle school and undergraduate levels to promote interest in biology in underrepresented groups. At the middle school level, the fellow will teach microbe-based modules to refugee girls to increase awareness of microbes (beneficial and harmful). At the undergraduate level, the fellow will recruit students from minority-serving programs to participate in a course-based undergraduate research experience (CURE), where students will conduct their own research based on the fellow's project. The bacterium Pseudomonas mendocina protects the nematode Caenorhabditis elegans from the pathogenic bacterium, P. aeruginosa. The fellow will passage P. mendocina between hosts in the presence or absence of P. aeruginosa while simulating vertical and horizontal transmission. After 15 passages, the fellow will measure P. mendocina growth rates and host survival, and assess genomic and transcriptomic changes in the bacterium. Additionally, the fellow will conduct a meta-analysis of the current literature to determine whether experimental findings align with systems in nature. The fellow will receive training in microbial characterization techniques, sequence analysis, and meta-analysis. The fellow will also gain teaching and communication skills through establishing a CURE and implementing science modules at a local middle school. 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.