Fig 5.
ylmC, ytaF, and ylzA are expressed during spore development. (A) Expression of transcriptional fusions of ylmC, ytaF, and ylzA to gfp, inserted at the nonessential amyE locus of a wild-type strain or the indicated mutant, during sporulation in DSM. PylzA* refers to a fusion bearing two substitutions in the −10 promoter element of a putative σF-dependent promoter (see the text for details). Samples were withdrawn from cultures at the represented times (in hours) after the onset of sporulation (or T0). The cells were stained with the membrane dye FM4-64 (middle column for each strain), prior to observation by fluorescence microscopy. The arrowheads point to the position of the mother cell (white) and forespore (yellow) compartments in the selected cells. Bar, 2 μm. (B) Schematic representation of the expression patterns found for the ylmC, ytaF, and ylzA genes; pale green denotes weak expression, and the darker green indicates stronger accumulation of GFP.