FIG. 2.

C-signal dependence of Ω4406 expression requires the upstream negative element. (A) Developmental expression from the 1.0-kb DNA segment containing the Ω4406 promoter fused to lacZ and integrated at the Mx8 phage attachment site in the chromosome of M. xanthus wild-type DK1622 (⧫) or csgA mutant LS203 in the absence (▪) or presence (▴) of an equal number of wild-type DK1622 cells (lacking lacZ but capable of C signaling). (B) Developmental expression from the 0.6-kb (bp −100 to 485) segment in wild-type DK1622 (⧫) or csgA mutant LS203 (▪). The meaning of points and error bars is the same as described in the Fig. 1 legend.