Fig. 5. tsh repression is not maintained by Wg or Dpp signaling. In all panels, Hth staining is in blue and Vg is in red. (A-C) Late third instar wing disc containing arr^– clones, induced by heat shock during the second instar. Clones are marked by the absence of GFP. hth is only de-repressed in arr mutant clones away from the AP boundary, while tsh is never de-repressed in the pouch (yellow arrowheads). (D-F) dTCF^DN expression in clones (GFP positive), induced by heat shock during the second instar. Clones far from the AP boundary in the pouch de-repress hth, but have no effect on tsh expression (yellow arrowheads). Note that in the hinge, both arr^– and dTCF^DN clones ectopically express tsh (A-F, white arrows), indicating a failure to maintain tsh repression in this domain. (G-K) dTCF^DN expression (GFP positive) in Med¹³ M+ clones induced in the second instar (8 clones scored). (G-I) hth, but not tsh, is ectopically expressed in mutant pouch cells (yellow arrowheads). (J) tsh is still repressed in a pouch clone (white outline) that no longer stains for Dll (violet), a marker of Wg signal transduction. (K) In the peripodial membrane the endogenous tsh and hth expression is unaffected by a large clone (white outline).