Transcription from the Complementary Deoxyribonucleic Acid Strands of Bacillus subtilis During Various Stages of Sporulation

Abstract

The messenger ribonucleic acid (mRNA) pattern of log-phase and sporulating cells of Bacillus subtilis has been analyzed by deoxyribonucleic acid (DNA)-RNA hybrid studies with the complementary-strand fragments of DNA. Approximately 80% of the mRNA of log-phase and sporulating cells from stages I, III, and IV hybridizes with the heavy DNA fragments, and 20% hybridizes with the light DNA fragments. Hybrid competition studies indicated that there was either a greatly reduced rate of transcription or a turn-off of some log-phase genes during the sporulation stages. However, a significant amount of log-phase gene transcription occurred even at late stages of sporulation. Similar studies indicate a significantly increased rate of transcription or a turn-on of sporulation phase genes during the latter stages of sproulation. There is a sequential increase in the amount of sporulation-specific transcription from both complementary-strand fragments of DNA. These results indicate that the RNA polymerase population in sporulating cells can transcribe both log-phase and sporulation-phase genes. MATERIALS AND METHODS Bacterial strain and media. B. subtilis 168 wild type was grown at 37 C in a modified Schaeffer medium (2 x SG) (10) for all experiments except for the preparation of DNA. For this purpose, cells were 775

Two polypeptides associated with the ribonucleic acid polymerase core of Bacillus subtilis during sporulation

“…BACTERIOL. I' sistent with earlier observations that sporulating cells contain mRNA's found in vegetative cell (5,6,24). Since vegetative holoenzyme would recognize vegetative gene promoters, it is likely that the sigma enzyme is continuing to transcribe these "vegetative genes" during sporulation.…”

“…Finally, the sequential appearance of the 8containing enzymes suggests that the sequential appearance of sporulation mRNA's (24) could be related to some sequential change in the property of the RPase during spore formation. One possibility is that these new forms of the enzyme recognize a new set of genes necessary for the morphological development of the spore.…”

“…B. subtilis 168 wild type was grown at 37°C in modified Schaeffer medium (2 x SG) (13) for all preparations of enzyme. To obtain maximum synchronous sporulation, cells were transferred three times at log stage to fresh 2 x SG medium as described previously (24). The final (fourth) 10-liter culture in the fermentor was stopped at the proper time by adding NaN3 (final concentration, 1 mM) and MgCl2 (final concentration, 1 mM) and by chilling rapidly by the addition of -70°C ice.…”

“…Several types of evidence indicate that specificity of transcription is altered during sporulation ofBacillus subtilis. Analyses of messenger ribonucleic acid (RNA) present in sporulating cells have indicated the presence of transcripts from genes expressed during both vegetative growth and sporulation and from genes expressed only during sporulation (5,6,24). The reduced ability of sporulating cells to replicate certain phage also suggests that the RNA polymerase (RPase) in sporulating cells may have altered specificity in recognizing or transcribing phage genes (10,19,25).…”

Coat protein synthesis during sporulation of Bacillus subtilis: immunological detection of soluble precursors to the 12,200-dalton spore coat protein

“…Evidence has accumulated which indicates that transcriptional (3,18) and translational (4,12,19) controls operate during sporulation. New RNA sequences are synthesized during development, and some RNA sequences found in dividing cells are no longer made (3,18). As a result, sporulation-specific polypeptides are synthesized and some polypeptides, characteristic of growing cells, are not (14).…”