Molecular interactions between Vestigial and Scalloped promote wing formation in Drosophila

Scalloped (Sd) and Vestigial (Vg) are each needed for Drosophila wing devel opment. We show that Sd is required for Vg function and that altering their relative cellular levels inhibits wing formation. In vitro, Vg binds direc tly to both Sd and its human homolog, Transcription Enhancer Factor-1. The interaction domains map to a small region of Vg that is essential for Vg-me diated gene activation and to the carboxy-terminal half of Sd. Our observat ions indicate that Vg and Sd function coordinately to control the expressio n of genes required for wing development, which implies that Vg is a tissue -specific transcriptional intermediary factor of Sd.