Asymmetric transcription during post-germinative development of Bacillus subtilis spores

The relative transcription from L and H strands of Bacillus subtilis DNA during consecutive stages of spore outgrowth was determined and compared to the transcription pattern during log-phase growth of vegetative cells. Pulses of [3H] uridine were administered during early, middle and late outgrowth phases of germination and the RNAs isolated. The asymmetry ratio of H/L as determined by hybridization at saturating RNA/DNA inputs showed a gradual decrease. During the period studied (10-90 and 90-160 min post-induction), about 50 and 35%, respectively, of the radioactive RNA consisted of ribosomal RNA transcripts. The decrease in the H/L asymmetry ratio was due predominantly to the appearance and accumulation of L strand transcripts and not to either changes in the quantity of H strand transcripts nor to fluctuation in the rate of rRNA synthesis.