(A,B,C,D,E) Wildtype stage 12 embryos showing founder cell specific expression of (A) opa in PS3-5 and PS9-12 PS, (B) Tsh in PS4-6 (C) Ubx in parasegment (PS) 7, (D) dpp in PS3 and PS7 and (E) Wg in PS8 in the visceral founder cells (arrows). (F,G,H,I,J) Forced expression of Org-1 in all cells of the visceral mesoderm leads to the expansion of (F) opa, (G) Tsh, (H) Ubx, (I) dpp and (J) Wg expression domains from the visceral founder cells (arrows) into the visceral fusion competent myoblasts (arrowheads). The visceral mesoderm is visualized by 3-Tubulin stainings.