A. Schematic of RhoBAD enhancer highlighting the positive (Ato and Abd-A) and negative (Sens) transcriptional inputs into the conserved RhoA and RhoD elements. The RhoB element drives gene expression in the embryonic head, the RhoA region drives gene expression within the abdominal ch organ (Cho) SOP cells, and the RhoD region drives gene expression within the C1 SOP cells of both the thorax and abdomen. B-C. Schematic of RhoA function in early (B) and late (C) SOP cells. In early SOP cells the thoracic and abdominal SOPs express Ato, which limits Sens-mediated repression of rho resulting in low levels of gene expression within both the thorax and abdomen. In late SOP cells, Ato has been degraded freeing Sens to bind RhoA and repress gene expression within the thorax. Within the abdomen, however, Abd-A continues to limit Sens binding allowing for enhanced rho gene expression and the induction of abdomen-specific oenocyte cells.