The expression patterns of Dlp and Ihog in the Drosophila wing disc. (A-C′) Antibody staining of Hh/Ptc (A,A′), Dlp/Ptc-β-Gal (B,B′) and Ihog/Ptc (C,C′) in wild-type wing discs. The Dlp protein level is elevated in the Ptc expression domain, whereas the Ihog level is reduced in this domain. (D) The intensity of Hh (A), Dlp (B) and Ihog (C) staining from selected areas (boxed) are plotted along the A/P axis. In the high Hh signaling area, the Dlp level is upregulated and the Ihog level is downregulated, suggesting distinct functions in Hh signaling.