Fig 5. Mutations detected in the proBA* operon in four lineages of the ΔargC proA* strain after adaptation for approximately 250 generations in M9/glucose.

A) Locations of point mutations; B) presence of point mutations in the population at the indicated time points. Lower-case letters indicate that the mutation was present in a fraction of the population based on Sanger sequencing. Each of these mutations was subsequently detected in individual colonies from the population, as well. Upper-case letters denote mutations that had swept the population to the limit of detection by Sanger sequencing.