FIG 7.

Northern blot analysis of MMC-induced differential expression of rhoL transcripts in RNA repair mutant strains. (A) The Northern blot was prepared with equal amounts of total steady-state RNA from S. Typhimurium 14028s WT, ΔrtcR, ΔrtcB, and Δrsr strains (untreated and treated with MMC) electrophoresed on a 1% agarose gel. The membrane was probed for rhoL transcripts. The genomic region carrying rhoL and rho is shown, with the primary and secondary promoters for the rho operon depicted by curved arrows (9) and the lengths of the leader regions and rho gene indicated. (B) The Northern blot was prepared with equal amounts of total steady-state RNA from S. Typhimurium 14028s WT, ΔrtcR, ΔrtcB, Δrsr, and ΔrtcA strains (untreated and treated with MMC) electrophoresed on an 8% acrylamide gel. The membrane was probed for rhoL transcripts. The Northern blots in panels A and B are representative of results from three biological replicates. The nucleotide (nt) lengths indicated for each Northern blot are from the RiboRuler low-range ladder (Thermo Fisher) included on the gels.