FIG 4.

Flagellar mutants make fewer pili per cell. (A) Microscopy images of pil-cys strains with pilus retraction obstructed with PEG-mal and labeled with AF488-mal. Scale bars, 5 μm. (B) Quantification of the percentages of piliated cells within populations of flagellar mutants that make one, two, or three or more pili. The bars indicate the mean and SEM of the results of 4 independent biological replicates. At least 20 cells were analyzed per replicate. Statistical comparisons were made using Sidak’s multiple-comparison test between the numbers of pili per cell for each strain. ***, P < 0.0005.