FIG. 2.

Stages of fruiting body formation in the pilA mutant. (A) Initial organization of cells after being spotted on agarose (0 h). (B) Rearrangement of cells into a matte (6 h). (C) Towers only three to four cell layers thick (9 h). (D) pilA mutant aggregation centers display tiers for a longer period of time than wild-type cells before becoming obscured by ECM material. Note that an aggregation center has two origins for a new tier, which is not often observed (12 h). (E) Mature fruiting body. pilA mutant fruiting bodies are often less compact and hemispherical than wild-type fruiting bodies (48 h). Bar, 0.1 mm. Pictures are derived from the same movie but not spatially aligned. The original movie on which this figure is based is available as Movie S2 in the supplemental material.