FIG. 2.

Northern blot analyses of genes whose transcription was induced under anaerobic conditions. For RNA preparation, cells were grown in synthetic medium without nitrate to an OD₅₀₀ of 0.5 and shifted to anaerobic conditions. RNA was isolated before (c₀) and 10, 20, 30, and 60 min after shift to anaerobic conditions. To ensure that the mRNA levels of the respective genes remained unchanged during the course of the experiment in an aerobically grown culture, RNA was also prepared from a nontreated culture 60 min after the shift (c₁). The RNA was separated on a denaturating RNA gel and blotted onto positively charged nylon membranes. The membranes were hybridized with digoxigenin-labeled RNA probes of the respective genes. Relevant transcripts are indicated by arrows. Schematic representations of the gene loci based on the sequence of S. aureus COL are shown.