FIG 5.

A model of the gene regulatory network promoting hormogonium development, depicting genes or gene clusters essential for functional hormogonia. Arrows indicate positive interactions between genes or their mRNA or protein products, and lines with bars indicate negative interactions. Timing of events, based on gene expression (1), is depicted above. Based on the evidence presented here, regulation of pilA by ogtA is posttranscriptional, and it is currently unknown if ogtA regulates other components of the type 4 pilus-like system in addition to pilA.