14-3-3 proteins are required for planar spindle alignment in wing disc epithelial cells. (A–D) Quantification of mitotic spindle alignments in 14-3-3ε^j2B10 (A) and 14-3-3ζ^12BL (B) MARCM clones, as well as in 14-3-3ε^j2B10 (C) MARCM clones in a 14-3-3ζ^12BL heterozygous background (14-3-3ζ^12BL/+, 14-3-3ε^j2B10) and with coexpression of 14-3-3ζ-RNAi (VDRC48724; 14-3-3ζ-RNAi, 14-3-3ε^j2B10; D). The red line shows the median angular deviation for each mutant condition compared with controls (green). n indicates the number of spindles observed. FRT82B (n = 33; A, C, and D), FRT42D (n = 46; B) for controls. *, P = 0.0171; ****, P < 0.0001; n.s., not significant (P > 0.05) by Kolmogorov–Smirnov test. (E and F) E-cadherin and Dlg localization in 14-3-3ε^j2B10 (E) and 14-3-3ζ-RNAi, 14-3-3ε^j2B10 (F) MARCM clones, respectively. Upper panels are xy images; lower panels are cross sections (xz). (G and H) Depletion of 14-3-3 proteins in wing discs induces basal cell delamination associated with apoptosis. Apoptotic cells (arrows) are labeled by anti–cleaved caspase 3 or anti–cleaved death caspase 1 (DCP-1) staining in MARCM clones of 14-3-3ζ^12BL/+, 14-3-3ε^j2B10 (G) and 14-3-3ζ-RNAi, 14-3-3ε^j2B10 (H). (I) Control MARCM clones expressing p35. (J) 14-3-3ε^j2B10 MARCM clones expressing p35 with 14-3-3ζ-RNAi exhibit mesenchymal-like morphology. MARCM clones were generated by using hsFLP UAS-mCD8-GFP; tub-Gal4 FRT82B tub-Gal80/TM6C (A and C–J) or hsFLP UAS-mCD8-GFP; FRT42D tub-Gal80; tub-Gal4/TM6B (B). Scale bars: 5 µm (A–D) and 10 µm (E–J).