FIG. 3.

Transcription of PA pathway genes was increased in Alt. 1 and Alt. 2 during exponential growth. Total RNA was isolated from mid-exponential cells (OD₆₀₀ of 0.50 to 0.65) grown in TH broth. RNA concentrations were determined by spectrophotometric absorbance at 260 nm. Total RNA (5.0, 2.5, and 1.25 μg) was separated on a denaturing agarose gel. RNA gels underwent Northern blotting, and the binding of DIG-labeled DNA probes was detected by CSPD development and then by autoradiography. Equal loading was confirmed by ethidium bromide staining of the gel and by probing for DNA gyrase (gyrA). RNA concentrations in μg are noted above the lanes in each image. Fresh RNA was isolated for each experiment, and the results presented here are representative of three independent preparations.