FIG. 2.

RNA primer extension analyses of V. cholerae wild-type O395 and a toxT_Δhth mutant strain (A) and toxT_Δpro and tcpA_Δpro mutant strains (B). Samples were collected at 1-h intervals after back dilution of an overnight culture grown in LB medium at 30°C 1:100 into fresh LB medium. A radiolabeled toxT primer was used. RNA collected from wild-type strain O395 after 2 to 3 h of growth was used as a positive control for the mutant strains in panel B.