NSF PRFB FY 2023: Genes on the move: the evolution of horizontal transfer in bacteria

Kosterlitz, Olivia, Seattle WA

Investigators

Abstract

This action funds an NSF Postdoctoral Research Fellowship in Biology for FY 2023, Integrative Research Investigating the Rules of Life Governing Interactions Between Genomes, Environment, and Phenotypes. The fellowship supports research and training of the fellow that will contribute to the area of Rules of Life in innovative ways. This project will focus on bacterial communities, which play crucial roles in maintaining the health of ecosystems, as well as in human health and disease. Specifically, the research aims to investigate how bacteria acquire new traits. The method that will be investigated is called horizontal gene transfer, or HGT. This is an essential yet overlooked aspect of bacteria. A well-known example of this process is the spread of antibiotic resistance between different species of bacteria. Through this work, the fellow will help to inform initiatives to combat the spread of antibiotic resistance. In addition, the fellow will participate in activities to inspire and engage the next generation of scientists through community outreach and mentorship programs. The fellow’s research program will use a combination of experiments and mathematical modeling to uncover the evolutionary rules governing the movement of genes between unrelated bacteria through HGT. In spite of the importance of plasmid-encoded traits to human, animal, and environmental health, we know little about how the spread of these important traits is affected by small changes in the plasmid’s core genes that help the plasmid replicate and transfer between bacteria by HGT. The fellow’s research program will focus on the evolution of plasmid core genes in various environmental and community contexts. Specifically, the project will create a detailed genotype to multi-dimensional phenotype map for a portion of a conjugative plasmid. This systematic mapping will explore how mutations in specific parts of the plasmid affect both its ability to horizontally spread, and the fitness of its bacterial hosts. To achieve this, the project will develop new methods for accurately and simultaneously measuring HGT and growth rates in multiple species of bacteria and use this data to build a mathematical model that can predict how plasmids will evolve under different environmental conditions. By shedding light on the complex interactions between genes, hosts, and environments in bacterial communities, this research will advance our understanding of fundamental biological concepts governing the ecology and evolution of bacterial communities and aid in combating the spread of antibiotic resistance. 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.