Author ORCID Identifier
https://orcid.org/0000-0001-6939-1351
Date of Award
Spring 5-11-2023
Document Type
Thesis (Ph.D.)
Department or Program
Microbiology and Immunology
First Advisor
Deborah A. Hogan
Second Advisor
Mary Lou Guerinot
Third Advisor
Carey D. Nadell
Abstract
Change is the only constant in life, and these changes, though random in nature, can have consequences. Quorum sensing is heterogeneous in phenotype and prone to negative selection. In P. aeruginosa, the regulator LasR is frequently non-functional in phylogenetically diverse isolates. Through repeated experimental evolution and mathematical modeling, we show that differences in growth enable lasR mutant evolutionary success and this requires a system enabling metabolic choices, known as carbon catabolite repression (or catabolite repression). The differences in catabolite repression between wild type and lasR mutants enable altered metabolite preferences, and the resulting differences in metabolic states enable intraspecies cross-feeding important for strain fitness. Cross-feeding within these clonally-derived populations promotes virulence factor production beyond either strain in isolation. The emergent properties inherent in populations with heterogeneous quorum sensing function likely impact community composition, structure, and function.
Recommended Citation
Mould, Dallas L., "CAUSES AND CONSEQUENCES OF LASR MUTANT SELECTION IN PSEUDOMONAS AERUGINOSA POPULATIONS" (2023). Dartmouth College Ph.D Dissertations. 195.
https://digitalcommons.dartmouth.edu/dissertations/195
Included in
Bacteriology Commons, Biodiversity Commons, Environmental Microbiology and Microbial Ecology Commons, Evolution Commons, Microbial Physiology Commons, Pathogenic Microbiology Commons, Population Biology Commons