Figure 1.

A genome-wide RNAi screen for genes required for Wingless secretion. (A) Schematic diagram of the reporters used. The signal peptide of sFluc stems from influenza haemagglutinin. (B) Downregulation of Wntless reduces secretion of WgRluc, but not sFluc. Knockdown of anti-apoptotic diap1 causes cell death and a reduction of both reporters in the media. Data represent means±s.d. (n=4), t-test ^*P<0.01 compared with GFP controls. (C) Summary of the screening protocol. DIAP1, Drosophila inhibitor of apoptosis 1; dsRNA, double-stranded RNA; GFP, green fluorescent protein; RNAi, RNA interference; RLU, relative luciferase units; sFluc, secreted form of Firefly luciferase; Wls, Wntless; WgRluc, Wingless–Renilla luciferase.