Figure 7 .

Loss of CK1α activates Wg signaling by promoting Arm accumulation. (A–E) Third instar wing discs; (A) wild type or (B–E) carrying CK1α^8B12 clones marked by the absence of GFP (green). (A) fz3–RFP is expressed as a stripe in the notum and more weakly in the central hinge and wing pouch. (B) CK1α^8B12 clones induce ectopic fz3–RFP (red) expression in the notum and pouch (arrowheads) but not in the lateral hinge (open arrowhead). (C–E) Arm (red) accumulates close to the D/V boundary (open arrowhead) and in CK1α^8B12 clones within the wing pouch (solid arrowhead). Single confocal sections show prominent Arm enrichment at the apical/lateral plasma membrane (D) and also more basally (E). (F–H) Eye discs containing clones marked by coexpression of GFP (green) and stained for Elav (red) and Sens (blue). The lack of photoreceptors in CK1α^8B12 clones (F) is rescued by expression of dominant negative dTCF (G). (H) UAS–dTCF^DN control clones do not affect photoreceptor differentiation.