title: Flow cytometric study of differentiating cultures of Bacillus subtilis.
abstract: We report on 1) the development of a flow cytometry-based technique for detecting beta-galactosidase in differentiating cultures of Bacillus subtilis and 2) the application of this technique in the study of early developmental gene expression. The problems associated with generating detectable signals (despite the small size of B. subtilis cells) have been overcome using the fluorogenic substrate 5-octanolyaminofluorescein di-beta-D-galactopyranoside (C8-FDG). Additionally, to control for background fluorescence during the staining process, we included a control population in the C8-FDG staining mixture that consists of cells devoid of the lacZ gene prestained with another dye, PKH26. The distinct emission spectra of C8-fluorescein and PKH26 allow nonspecific C8-FDG staining in this control population to be monitored using two-color analysis. This technique has been applied in the study of developmental gene expression in sporulating cultures of B. subtilis, and it has been found that such cultures are heterogeneous, comprising two cell populations. One population is induced for expression of early sporulation genes, which is determined using lacZ fusions, whereas the other remains uninduced. These results have allowed us to understand better the patterns of gene expression exhibited by wild-type and mutant cultures early during the development process of spore formation.
authors.affiliation: Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, USA.
authors.forename: J D
authors.initials: JD
authors.lastname: Chung
authors.forename: S
authors.initials: S
authors.lastname: Conner
authors.forename: G
authors.initials: G
authors.lastname: Stephanopoulos
mesh_terms: D001412:Bacillus subtilis / Q000201:enzymology* / Q000235:genetics / Q000502:physiology; D001426:Bacterial Proteins / Q000032:analysis* / Q000096:biosynthesis / Q000235:genetics / Q000502:physiology; D004187:Disaccharides / Q000032:analysis; D004790:Enzyme Induction; D005434:Flow Cytometry / Q000379:methods*; D005452:Fluoresceins / Q000032:analysis; D005456:Fluorescent Dyes / Q000032:analysis; D015964:Gene Expression Regulation, Bacterial; D017930:Genes, Reporter; D009930:Organic Chemicals; D011494:Protein Kinases / Q000235:genetics / Q000502:physiology; D011993:Recombinant Fusion Proteins / Q000032:analysis* / Q000378:metabolism; D012808:Sigma Factor; D013171:Spores, Bacterial; D014157:Transcription Factors; D001616:beta-Galactosidase / Q000032:analysis* / Q000235:genetics / Q000378:metabolism
chemical_list: C096840:5-octanoylaminofluorescein digalactopyranoside; D001426:Bacterial Proteins; D004187:Disaccharides; D005452:Fluoresceins; D005456:Fluorescent Dyes; D009930:Organic Chemicals; C070080:PKH 26; D011993:Recombinant Fusion Proteins; D012808:Sigma Factor; C095876:SpoVG protein, Bacillus subtilis; D014157:Transcription Factors; C075521:kinA protein, Bacillus subtilis; C092468:spoIIR protein, Bacillus subtilis; C030069:spore-specific proteins, Bacillus; D011494:Protein Kinases; D001616:beta-Galactosidase