Fig. 3. (A-D'") Localisation of Drosophila Par-6 in sdt^K85-mutant pupal photoreceptor cells upon expression of different Sdt transgenes. Optical cross sections of pupal eyes at 40-45% p.d., before formation of the stalk membrane. sdt^K85 mutant MARCM clones expressing different sdt transgenes, stained with anti-Par-6 (red) and anti-E-cadherin to stain the zonula adherens (blue). Mutant cells expressing a transgene are visualised using expression of GFP (green). Cells not expressing GFP are wild-type and serve as a control to demonstrate that Par-6 localises apically in PRCs at this stage. In sdt^K85 mutant PRCs (A-A'"), Par-6 is reduced in amount and delocalised from the apical membrane (arrows). In sdt^K85 mutant PRCs that express Sdt-B2 (B-B'"), Par-6 localises apically. In most sdt^K85-mutant PRCs that express Sdt-A (C-C'"), Par-6 localises apically but, occasionally, also basolateral (arrows). Expression of Sdt-PDZ in sdt^K85 mutant PRCs does not restore apical localisation of Par-6 (D-D'").