FIG 2.

Effects of fliF deletion on flagellar gene transcription and motility. (A) Motility of ΔfliF mutant was assessed on 0.4% agar plates after 7 days of incubation under microaerobic conditions. Measurements indicate the diameter of the halo around the site of inoculation. The halo diameter for the wild type was 36 ± 2 mm, and that for the ΔfliF mutant was 7 ± 1 mm. (B) The number of flagella per cell was analyzed by electron microscopy after negative staining of cells. At least 115 cells were visualized per strain. (C) Transcript levels of flaB and flgE (left) and flaA (right) were detected by qRT-PCR. All results are significantly different from that for the wild type (P < 0.03). (D) Immunoblot of FlhA from membrane fractions. Each lane contains 20 μg protein. An immunoblot of KatA from the same membrane fractions was used as a loading control. Each lane contains 4 μg protein.