Use of lacZ Gene Fusions to Determine the Dependence Pattern of the Sporulation Gene spoIID in spo Mutants of Bacillus subtilis

Microbiology Unit, Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK ABSTRACT SUMMARY: The spoIID gene, which is involved in Bacillus subtilis sporulation, was fused to the β-galactosidase gene, lacZ , of Escherichia coli so that the expression of β-galactosidase would be under the control of the spoIID locus. When the fused product was inserted into the B. subtilis chromosome, production of β-galactosidase indicated that the spoIID gene was expressed 1.5 h after the start of sporulation. When the spoIID:: lacZ fusion was inserted into the chromosome of sporulation mutants, all strains carrying spoO lesions and those with mutations in spoIIA , spoIIE and spoIIG loci failed to make β-galactosidase. The proposed provisional order of expression of operons governing stage II is spoIIA [ spoIIG , spoIIE ] [ spoIID , spoIIB , spoIIF ]. Present address: Dept. de Genetica, Univ. Autonoma de Barcelona, Bellaterra - Barcelona, Spain.