Fig. 8. Ft intersects Wg signaling downstream of the Wg ligand. (A-C',E). Expression of Wg (red) in the DV boundary (arrow, A), Q-vg-lacZ (green, A) and Dll (green, E) in the pouch region is extinguished in vg¹ mutant wing discs. Misexpression of Wg (B) or loss of Ft in somatic clones (C) activates Q-vg-lacZ (B,C', green) in vg¹ mutant wing discs. Higher magnification (C') of boxed area in C to reveal activation of Q-vg-lacZ (green) in ft mutant clones (ft^fd/ft^fd, marked by loss of GFP, blue). (D,F-G') ft^fd vg¹ (D,F) or N^ts/Y; ft^fd/ft⁴²² (G,G') mutant wing imaginal discs do not express Wg (red) in their presumptive DV boundaries (arrows). Q-vg-lacZ (D',G'; green) and Dll (F, green) are activated in these discs. (H,H') Dll (red) and en-Gal4 (green) expression pattern in wild-type wing imaginal discs. Broken lines in this and subsequent figures indicate the AP compartment boundary. (I-J') Expression of GPI:DFz2 in the posterior wing compartment (en-Gal4/UAS-GPI:DFz2, green) downregulates the expression of Dll (red) in wild type (I,I') but not in the ft^fd mutant disc (J,J'). (K,L) fz^H51, fz2^C1 double mutant clones induced 48-72 hours after egg laying in wild type (K) and ft^fd mutant (L) wing imaginal discs do not survive, as revealed by the absence of non-GFP cells, whereas their twins do (cells with higher levels of GFP). (M-M') fz^H51, fz2^C1 double mutant clones in ft^fd mutant discs can be recovered when induced 24 hours prior to dissection. These clones (arrows), however, do not show Dll expression (red).