Strip and Cka control epithelial tissue integrity in Drosophila epithelia. (A–C) Confocal projections through medial (top) or basal (bottom) regions of wing discs expressing GFP (green) in a stripe of cells under control of the ptc-GAL4 driver, either alone (A) or together with dsRNA targeting Strip (B) or Cka (C). Discs were stained with DAPI (blue) to visualize nuclei and with anti–cleaved caspase 3 (Casp3) antibody (red) to visualize apoptotic cells. Arrowheads indicate the transgene expression domain within the wing pouch. Arrows indicate the transgene expression domain within the hinge region. (D–G) Confocal projections of wing discs (top row) expressing GFP (green) and P35, either alone (D) or together with dsRNA targeting Strip (E), Cka (F), or Slik (G). Discs were stained with DAPI (blue) to visualize nuclei and with anti-MMP1 antibody (red). x–z sections of the same discs (bottom row) generated by orthogonal projection.