Bacterial anti-phage defence as a gatekeeper of prophage evolution
Supervisors:
Prof Andy Roe, University of Glasgow
Dr Giusy Mariano, University of Glasgow
Dr Suzanne Humphrey, University of Strathclyde
Project Summary:
Temperate bacteriophages are major drivers of bacterial evolution, integrating into bacterial chromosomes as prophages and facilitating the acquisition of genes that can alter bacterial fitness, adaptation and virulence. Despite their importance, we understand relatively little about the host factors that determine whether an invading temperate phage successfully establishes as a prophage, persists within a bacterial population, or is subsequently induced.
This project will investigate whether bacterial anti-phage defence systems act as evolutionary gatekeepers of prophage acquisition and persistence. Using defined Escherichia coli backgrounds and toxin-deleted prophage models, the student will determine how selected defence systems affect distinct stages of the temperate phage lifecycle, including establishment, maintenance and induction. Defence–prophage interactions producing strong phenotypes will then be investigated mechanistically to determine how individual defence systems interfere with these processes. Finally, the project will examine the consequences of defence and prophage carriage for bacterial fitness across different genetic backgrounds and physiologically relevant environmental conditions.
By connecting bacterial immunity with the biology of temperate phages, this project will address how defence systems shape horizontal gene transfer and the evolutionary trajectories available to bacterial populations. The student will develop interdisciplinary expertise in phage biology, molecular microbiology, bacterial genetics and mechanistic analysis while addressing a fundamental question in microbial evolution.