FIG. 4.
Transcription from the ctc promoter is directed by both σB and σF. Fluorescence of green fluorescent protein (GFP) expressed under the control of the ctc promoter was monitored by fluorescence microscopy 1 and 2 h after the start of sporulation in cells wild type for sigB and sigF (KC495), with a deletion of sigB (KC496), with a deletion of sigF (KC504), or with a deletion of both sigF and sigB (KC505). Cell membranes were stained with trimethylammonium diphenyl-hexatriene p-toluenesulfonate. One-second exposures were captured with Metamorph version 4.6 (Universal Imaging) with autoscaling on.