USE OF GREEN FLUORESCENT PROTEIN FOR VISUALIZATION OF CELL-SPECIFIC GENE-EXPRESSION AND SUBCELLULAR PROTEIN LOCALIZATION DURING SPORULATIONIN BACILLUS-SUBTILIS

We report the use of the green fluorescent protein (GFP) of Aequorea v ictoria to visualize cell-specific gene expression and protein subcell ular localization during sporulation in Bacillus subtilis. Sporangia b earing the gene (gfp) for the green fluorescent protein fused to genes under the control of the sporulation transcription factor sigma(F) ex hibited a forespore-specific pattern of fluorescence. Forespore-specif ic fluorescence could be detected with fusions to promoters that are u tilized with low (csfB) and high (sspE-2G) efficiency by sigma(F)-cont aining RNA polymerase. Conversely, a mother cell-specific pattern of f luorescence was observed in sporangia bearing a transcriptional fusion of gfp to a spore coat protein gene (cotE) under the control of sigma (E) and an in-frame fusion to a regulatory gene (gerE) under the contr ol of sigma(K). An in-frame fusion of gfp to cotE demonstrated that GF P can also be used to visualize protein subcellular localization. In s porangia producing the CotE-GFP fusion protein, fluorescence was found to localize around the developing spore, and this localization was de pendent upon SpoIVA, a morphogenetic protein known to determine proper localization of CotE.