THE TRANSCRIPTIONAL ORGANIZATION OF THE BACILLUS-SUBTILIS 168 CHROMOSOME REGION BETWEEN THE SPOVAF AND SERA GENETIC-LOCI

The genetic organization of the spoVAF-serA area of the Bacillus subti lis chromosome and its putative transcription map have been derived fr om analysis of the nucleotide sequence. In order to confirm this trans cription map as regards size of transcripts and to determine growth co nditions for their appearance, we undertook Northern hybridization ana lysis of total RNA from vegetatively growing and sporulating cells. Tw enty-three distinct transcripts were thus identified, 14 of which were predicted from sequence analysis and nine of which were not predicted . Eight of the latter are homologous to open reading frames identified by sequence analysis but were not expected, since no obvious promoter or terminator was found in the sequence. The last unexpected transcri pt does not correspond to an ORF and might identify a novel gene. Thre e predicted transcripts were not detected. The transcripts were classi fied in four groups as (i) constitutive, (ii) regulated by nutritional depletion, (iii) specific for sporulation, and (iv) possibly regulate d temporally. These studies demonstrate that systematic Northern analy sis of a bacterial chromosome region is a useful complement to sequenc e analysis.