The apical epithelial domain is expanded in obe mutants. (A–D) Localization of Crumbs, aPKC, and Par-3 in wild-type (WT) and obe¹/obe² embryos at stage 7. (E) Merged image of the embryos in B and D showing expansion of the Crumbs apical domain (and the basolateral displacement of Par-3). (F–H) Cortical intensity of Crumbs (F), aPKC (G), and Par-3 (H) along the lateral membrane of wild-type and obe¹/obe² embryos in stage 7 (0 µm is the most apical plane). The Crumbs and aPKC domains were expanded in obe mutants (0.5–4.0 µm) compared with wild type (0.5–2.0 µm; n, four to six embryos per genotype and three to six edges per embryo). Error bars indicate the SEM between embryos. The obe¹/obe² mutant embryos were the progeny of obe¹/obe² females crossed to obe²/+ males. (A and C) Anterior left, dorsal up. (B, D, and E) Cross sections, apical up. Bars, 10 µm. See also Fig. S3.