Cell morphology drives spatial patterning in microbial communities

Authored by Kevin R Foster, William P J Smith, Yohan Davit, James M Osborne, Wook Kim, Joe M Pitt-Francis

Date Published: 2017

DOI: 10.1073/pnas.1613007114

Sponsors: European Union

Platforms: No platforms listed

Model Documentation: Other Narrative

Model Code URLs: Model code not found

Abstract

The clearest phenotypic characteristic of microbial cells is their shape, but we do not understand how cell shape affects the dense communities, known as biofilms, where many microbes live. Here, we use individual-based modeling to systematically vary cell shape and study its impact in simulated communities. We compete cells with different cell morphologies under a range of conditions and ask how shape affects the patterning and evolutionary fitness of cells within a community. Our models predict that cell shape will strongly influence the fate of a cell lineage: we describe a mechanism through which coccal (round) cells rise to the upper surface of a community, leading to a strong spatial structuring that can be critical for fitness. We test our predictions experimentally using strains of Escherichia coli that grow at a similar rate but differ in cell shape due to single amino acid changes in the actin homolog MreB. As predicted by our model, cell types strongly sort by shape, with round cells at the top of the colony and rod cells dominating the basal surface and edges. Our work suggests that cell morphology has a strong impact within microbial communities and may offer new ways to engineer the structure of synthetic communities.

Tags

Competition Evolution self-organization Model growth Biofilms Forces Biofilm structure formation Bacterial shape Adhesion Cell morphology Biophysics Synthetic biology