Ci acts epistatically to Hh. (A, D, G, and J) wg mRNA expression patterns, in late stage 10 embryos: (A) wild type, (D) hhGS1 mutant, (G) ciD mutant, and (J) hhGS1 ciD double mutant. (B, E, H, and K) gsb mRNA expression patterns late stage 10 embryos: (B) wild type, (E) hhGS1 mutant, (H) ciD mutant, and (K) hhGS1 ciD double mutant. (C, F, I, and L) ptc mRNA expression patterns, stage 11 embryos: (C) wild type, (F) hhGS1 mutant, (I) ciD mutant, and (L) hhGS1 ciD double mutant.