Fig. 4. nmo modulates Mad-dependent target gene expression and the pMad gradient. (A) vg^Q-lacZ expression in the wild-type Drosophila third instar wing imaginal disc. (B) vg^Q expression is abolished in the dorsal wing pouch when UAS-nmo is expressed using the dorsal-specific driver ap-Gal4. (C,D) nmo^DB24 somatic clones (marked by the absence of GFP, green). (E) Expression of vg^Q-lacZ is increased in the clone abutting the A/P boundary (arrow) but shows no detectable change in the clone further away from the levels of highest Dpp signaling, in which nmo expression is normally low (arrowhead). (F-H) Salm expression in wild-type, nmo^DB24/nmo^adk2 and omb>2x nmo third instar wing discs. The width of Salm expression along the D/V boundary is indicated by a white line. (I-K) nmo^lacZ expression in late third instar stage wing discs (green) co-localizes in the L3 and L4 vein primordia flanking the A/P boundary with highest levels of pMad staining (red in J,K). (L-N) nmo^DB24 somatic clones (marked by the absence of GFP, green). (M,N) pMad staining is unchanged in nmo clones. (O-Q) pMad staining in wild-type (O), nmo^DB24/nmo^adk2 (P) and omb>1x nmo (Q) discs. Arrowheads indicate the position of peaks of pMad staining.