Expression of toxR in different mutations of V. cholerae. (A) Activity of P
-luxCDABE reporter constructs (blue bars) in V. cholerae wild type and virulence regulatory mutants. Cultures were grown at 37°C overnight. Units are arbitrary light units/OD600. The results are the average of three experiments ± SD. (B) Analysis of samples in (A) by Western blot with anti-ToxR antiserum.