Figure 7. Org-1 is a direct regulator of dpp and wg expression in the circular visceral muscle founder cell lineage.

A) Schematic diagram of the genomic region used for the generation of the dppPB reporter. The predicted T-Box binding site is indicated in the blow-up view. (B) dppPB driven GFP expression in parasegment (PS) 3 (asterisk) and PS6-7 (bracket) of a stage 11–12 embryo. (C) Stage 11–12 org-1 mutant embryo carrying dppPB-GFP showing complete absence of visceral GFP transcript. (D) The dppPB reporter (GFP) is coexpressed with Org-1 in visceral mesodermal PS3 (asterisk) and PS6-7 (bracket). (E) The dppPB-OrgImut-GFP enhancer construct displays nearly complete loss of reporter activity in PS3 and PS7. (F) Schematic diagram of the genomic region used for the generation of the wgXC reporter. The predicted T-Box binding site is indicated in the blow-up view. (G)The wgXC enhancer fragment drives GFP expression in the visceral founder cells of parasegment (PS) 8 (asterisk) of a stage 11–12 embryo. (H) Complete absence of visceral GFP expression in a stage 11–12 org-1 mutant embryo carrying wgXC. (I) wgXC reporter signal (GFP) is colocalized with Org-1 in visceral mesodermal PS8 (asterisk). (J) The wgXC-OrgImut-GFP reporter shows nearly complete loss of reporter activity in PS8. (K) Amplicons covering the T-Box binding sites (indicated in A and F) and an ey exonic amplicon as negative control were assayed by qPCR for enrichment in Anti-Org-1 ChIP. Three independent biological replicates were used to generate the average bar normalized to negative controls from the C15 gene. The Org-1 consensus motif identified by SELEX (Schaub et al., 2012) is visualized by its sequence logo.