TABLE 1.

B. subtilis strains used in this study

Straina	Relevant genotype
JH642	trpC2 phe-1
JH11134	amyE::app-lacZ::aphc ΔsinR::Phlrb
JH14270	amyE::app-lacZ::aphc
JH14271	amyE::app-lacZ::aph ΔscoC::cat
JH14272	amyE::opp-lacZ::aph ΔscoC::cat
JH14279	amyE::opp-lacZ::aphd
JH17280	amyE::opp-lacZ::aph spo0A12
JH14281	amyE::app-lacZ::aph spo0A12
JH14282	amyE::opp-lacZ::aph abrB::Tn917mls
JH14283	amyE::app-lacZ::aph abrB::Tn917mls
JH14285	amyE::app-lacZ::aph spo0A12 abrB::Tn917mls
JH14286	amyE::opp-lacZ::aph spo0A12 abrB::Tn917mls

^aAll JH strains are derivatives of JH642 and therefore carry the trpC2 phe-1 auxotrophic markers and the app frameshift mutation (12). 

^bFrom strain IS720 (14). 

^cObtained by transformation of strain JH642 with linearized plasmid pJA143. 

^dObtained by transformation of strain JH642 with linearized plasmid pJM6178. Escherichia coli DH5α competent cells (Bethesda Research Laboratories) were used for plasmid construction and propagation. The app-lacZ fusion vector pJA143 is a pJM115 derivative carrying the 1.3-kb EcoRI-BglII fragment from pJH6186 (12). The opp-lacZ fusion plasmid pJM6178 contains a 1.2-kb HindIII-ClaI blunt-ended fragment carrying the oppA promoter cloned in pJM115 (25). pJM115 is a transcriptional fusion vector derivative of pDH32 in which the chloramphenicol resistance gene has been replaced with the kanamycin resistance gene (20). The multicopy plasmids pJM2491 and pJM2493 carrying the scoC locus or the scoC promoter region only, respectively, were constructed in the multicopy vector pBS19 and were described by Perego and Hoch (26). Plasmid DNA was prepared by the procedure of Birnboim and Doly (2). DNA manipulations were performed by standard methods (15). B. subtilis chromosomal DNA was prepared by using the Marmur method (16). Transformations were performed by the method of Anagnostopoulos and Spizizen (1) with 1 μg of plasmid DNA or 0.1 μg of chromosomal DNA. Schaeffer’s agar plates (29) supplemented with 5 μg of chloramphenicol, ml⁻¹, 1 μg of erythromycin ml⁻¹, 2 μg of kanamycin ml⁻¹, or 2.5 μg of phleomycin ml⁻¹ were used for selection.