FIG. 8.

culB⁻ pkaR⁻ mutants display an increased sensitivity to exogenous DIF in submerged culture. (A) culB⁻ pkaR⁻ cells and pkaR⁻ cells were incubated at low density in submerged culture for 48 h. The percentage of vacuolated stalk cells was determined at different DIF concentrations. The mean and standard error of triplicate determinations are shown. (B) An inhibitor of DIF biosynthesis, cerulenin, inhibits the stalk-like cell differentiation of culB⁻ pkaR⁻ cells in submerged culture. culB⁻ pkaR⁻ cells were incubated for 48 h under the same conditions as in panel A in the presence of cerulenin.