Evolutionary rescue of spherical <i>mreB</i> deletion mutants of the rod-shape bacterium <i>Pseudomonas fluorescens</i> SBW25.

ABSTRACT: Maintenance of rod-shape in bacterial cells depends on the actin-like protein MreB. Deletion of mreB from Pseudomonas fluorescens SBW25 results in viable spherical cells of variable volume and reduced fitness. Using a combination of time-resolved microscopy and biochemical assay of peptidoglycan synthesis, we show that reduced fitness is a consequence of perturbed cell size homeostasis that arises primarily from differential growth of daughter cells. A 1000-generation selection experiment resulted in rapid restoration of fitness with derived cells retaining spherical shape. Mutations in the peptidoglycan synthesis protein Pbp1A were identified as the main route for evolutionary rescue with genetic reconstructions demonstrating causality. Compensatory pbp1A mutations th

SUBMITTER: Yulo PRJ 

PROVIDER: S-EPMC11957537 | biostudies-literature | 2025 Mar

REPOSITORIES: biostudies-literature