Regulation of flagellar-associated genes and swimming motility. (A) Cluster analysis of flagellar-associated genes with decreased (green), increased (red) or no change (black) in expression in each mutant compared to K56-2 according to microarray analysis. Arrows indicate putative (dashed lines) or experimentally-determined (solid lines) transcriptional units. Gene name and function are derived from B. cenocepacia . Mean change (fold) in expression is indicated for the displayed group of genes for each mutant. Swimming motility was assessed by measuring zones of growth of cultures at (B) 22°C or (C) 28°C. Significantly different swimming motilities were observed for the QS mutants compared to K56-2 at 22°C and 28°C (***, P < 0.001, two-way ANOVA) (Fig. 3). All values are the means ± SEM of triplicate cultures and are representative of two individual trials.