Figure 2

Detection of transcriptional control of RgsA (1698) sRNA in P. aeruginosa and in P. fluorescens by Northern blot. a. Hybridization of cross-linked total RNA from P. aeruginosa PAO1 (wt), PAO6281 (gacA mutant) and PAO1-rpoS (rpoS mutant) with a double-stranded DNA probe prepared with primers 1698F (PAO1) and 1698R (PAO1) (additional file 3). RNA preparations were obtained from PAO1 (wild-type) in exponential phase (OD₆₀₀ ≅ 0.8) and stationary phase (OD₆₀₀ ≅ 4.9); from PAO6281 (gacA) in exponential phase (OD₆₀₀ ≅ 0.7) and stationary phase (OD₆₀₀ ≅ 4.8); from PAO1-rpoS (rpoS) in exponential phase (OD₆₀₀ ≅ 0.7) and stationary phase (OD₆₀₀ ≅ 5.0).b. Hybridization cross-linked total RNA from P. fluorescens CHA0 (wt), CHA89 (gacA mutant) and CHA815 (rpoS mutant) with a double-stranded DNA probe prepared with primers 1698F (CHA0) and 1698R (CHA0) (additional file 3). RNA was extracted from CHA0 (wild-type) in exponential phase (OD₆₀₀ ≅ 0.5) and stationary phase (OD₆₀₀ ≅ 6); CHA89 (gacA) in exponential phase (OD₆₀₀ ≅ 0.6) and stationary phase (OD₆₀₀ ≅ 6); CHA815 (rpoS) in exponential phase (OD₆₀₀ ≅ 0.6) and stationary phase (OD₆₀₀ ≅ 5.0). c. Hybridization of the same RNA preparations from P. fluorescens as in b, with an RsmZ probe synthesized with primers RsmZF (CHA0) and RsmZR (CHA0) (additional file 3). As a loading control, 5S rRNA was revealed in all samples with a probe synthesized with primers 5S rRNA-1 and 5S rRNA-2 (additional file 3). E: exponential phase, S: stationary phase.