Fig 1. An in vivo RNAi screen identifies exocyst components as candidate regulators of Wg secretion.

(A) A total of 394 genes involved in intracellular transport were selected as input for the in vivo screen (see Methods) and some of the functional categories are shown in the pie chart. All the 394 genes were screened in vivo using wg-GAL4 for the expression of RNAi in the Wg producing cells. (A’) Distribution of the phenotypes obtained is as follows, 282 no phenotype, 26 lethal (larval/pupal) and 86 wing notch phenotypes. 6 out of 7 screened components of the exocyst complex (marked in black) showed wing notch phenotype upon depletion (see also S1 Table). (B–B”) Wing notch phenotype obtained upon depletion of control (gene not related to Wnt signaling) Relish (Rel) (B), Sec6 (B’) and Evi (B”) in Wg producing cells. (C–D) Total Wg staining on discs with depletion of Sec6 (C–C”) or Evi (D–D”) in the posterior compartment of the disc (marked by GFP). (E) Total Wg accumulation in sec6^ex15 mutant clones (marked by absence of GFP). (F) XZ section across the sec6^ex15 mutant marked by blue lines in E. N≥4 wing discs for C and D and N = 10 for E and F; scale bars 20 μm. a.u. = arbitrary unit. AP = Anterior-Posterior boundary.