Fig. 5. Lack of integrin function in the wing disc reproduces the phenotype resulting from di overexpression. (A-F) Confocal sections of late third-instar wing discs containing groups of cells in the posterior (p) compartment lacking the PS subunit, marked by the absence of GFP (white in A and C) or PS (green in E). (B) Staining of filamentous actin with Rhodamine-phalloidin (RP) shows that lack of integrin function in the discs leads to the formation of extra folds. (D) A confocal section of a wing disc stained with an antibody that labels the basal matrix (ecm) shows that the matrix associated with the posterior PS mutant cells looks disorganised and hollow. (E,F) xz confocal sections of wing discs stained with Rhodamine-phalloidin (red) and an anti-PS antibody (green) shows that wing epithelial cells lacking the PS integrins (between arrows) are reduced in height when compared with the wild-type neighbours. Expression of PS in cells of the peripodial membrane (at the top) is not affected. (G) Cross-sections of these mutant discs show that the lack of PS induces a change in cell shape from a columnar to a cuboidal morphology (arrows indicate the height of the cells). Bar in A, 30 µm for A-D; a, anterior compartment.