Flagellar morphology of the wild-type BGR1 and the QS mutants.

<p><b>A</b>. TEM images showing polar and nonpolar flagellar formation in the wild-type BGR1, the <i>tofI</i> mutant BGS2, and the <i>tofI</i> mutant BGS2 cells supplemented with 1 µM of C8-HSL, and the <i>qsmR</i> mutant BGS9 cells taken from the O and I regions of the swim assay plates after culture for 20 h at 28°C. <b>B</b>. Magnified TEM images of nonpolar flagella in the <i>tofI</i> mutant BGS2 cells and the <i>qsmR</i> mutant BGS9 cells. Yellow circles indicate the sites of flagellar formation. Bars = 1 µm.