Identification of Additional Genes under the Control of the Transcription Factor sF of Bacillus subtilis

We describe the identification of five transcriptional units under the control of the sporulation transcription factor sF in Bacillus subtilis. These are csfA, csfB, csfC, csfD, and csfF, located at approximately 230&, 2&, 316&, 205&, and approximately 290&, respectively, on the genetic map. Null mutations in csfA, csfB, csfC, or csfD, either alone or together, do not cause a noticeable defect in sporulation or germination. The sF factor of Bacillus subtilis is an RNA polymerase sigma factor that governs cell-type-specific gene transcription during the process of sporulation (for a review, see references 5 and 10). The sF factor directs gene expression in the fore-spore compartment of the sporangium at the polar septation stage of development. It is required for the appearance of two later-acting sporulation-specific sigma factors, sE and sG, as well as for morphological development of the forespore itself. At present, only four genes whose transcription is under the control of sF have been reported. These are spoIIIG, the structural gene for sG (15, 18); spoIIR, a gene whose produc