Fig. 1. Sax antagonizes Gbb function, whereas Tkv is required to mediate both Gbb and Dpp. (A,F) Overexpression of gbb at 25°C (A) or dpp at 18°C (F) in the wing disc produce wings divided into four classes by phenotypic severity. (B-E,G,H) Percentage of wings in each class produced by gbb or dpp overexpression alone (yellow) or in combination with changes in Tkv or Sax levels (red). (B) gbb overexpression wing phenotypes (yellow) are very strongly suppressed by overexpression of wild type sax (red), while (C) increasing Tkv levels in the presence of excess Gbb enhances the gbb overexpression phenotype. (D) Reducing the level of endogenous Sax strongly enhances gbb overexpression. (E) Reducing the level of endogenous Tkv results in a strong suppression. (G) Reducing the level of endogenous Sax mildly suppresses dpp overexpression wing phenotypes. (H) Reducing Tkv levels strongly suppresses dpp overexpression. (I) Ligand overexpression in different mutant backgrounds.