FIG 2.
(A) Schematic diagram of mutant construction. The double-crossover event integrating plasmid DNA on the chromosome is schematically shown. (B) RT-PCR experiment showing that the σK promoter moved upstream of spsB in strain GC346 is able to start transcription of the operon. In strain GC355, deleted of the promoter and first gene of the operon, transcription is impaired. (C) Fluorescence microscopy analysis of a strain derivative of GC346 carrying an spsB::gfp fusion. A representative microscopy field is observed by phase contrast (PC) and fluorescence (FM) microscopy. A fluorescence signal was observed around forming spores but not in cells that have not entered the sporulation cycle.