FIG. 2.

MqsR causes elongation of bacterial cells. Expression of mqsR was induced in the logarithmic growth phase at time zero by addition of 1 mM l-arabinose to a culture of HM21Δ cells bearing plasmids pAT3 (ygiT expression) and pTX3 (mqsR expression). An uninduced culture of the same strain was used as a control. Samples were taken at the times indicated, and bacteria were stained with the SYTO BC dye and examined by epifluorescence microscopy. Control bacteria (A) and the MqsR-arrested bacteria (B) were observed 4 h after induction of mqsR. (C) Average lengths of 100 bacterial cells. Filled squares, MqsR-expressing bacteria; open squares, uninduced control. The vertical bars indicate the limits of cell length (the longest and shortest bacteria in a set of cells).