Figure 4.

Matrix gene expression of evolved strains corresponds to colony morphology. Select colony-purified evolved strains, the ancestral strain, and a sinR null mutant of the ancestor were engineered to contain a luciferase reporter under the control of the promoter for either epsA or tapA. All strains were grown and tested in LB. Luciferase activity representative of matrix gene expression was measured every ten minutes and was normalized by culture density. The bottom panels are identical to the top panels but are re-scaled without the sinR null strain. Results represent the average of at least four replicates and error bars represent the standard deviation.