Figure 7.

Northern blot analysis of the hisG-lacZ and the lacZ mRNA. (A) RNA was isolated from the wild type and the mutant harboring pQFhis after 0 and 3 hr of the nutritional downshift. Addition of amino acids (10 mg/ml) to the Mops medium was indicated above. RNA (10 μg) was used for hybridization. Arrows indicate the position of 23S rRNA. The fluorescein-labeled lacZ probe was used. (B) RNA was isolated from the wild type and the mutant after 0 and 1 hr of the nutritional downshift. Isopropyl-1-thio-β-d-galactoside (1 mM) was added to the Mops medium to induce the chromosomal lacZ gene.