Synthesis of spoIIA and spoVA mRNA in Bacillus subtilis

The expression of the spoIIA and spoVA sporulation loci of Bacillus subtilis was examined by using DNA-RNA hybridization to detect the time of appearance of their corresponding mRNA molecules in wild-type and asporogenous mutants of B. subtilis. From the size of the mRNA molecules it is clear that both the spoIIA and spoVA loci are polycistronic operons. Neither of the mRNA molecules is polyadenylated. The results also indicate the spoIIA operon is regulated by two promoters which become functional at different times.