Epithelial cysts in cyst-compromised embryos maintain epithelial polarity. (A and B) Staining of cyst RNAi (A) and cyst¹(M/Z) (B) embryos compared with wild-type controls for the apical markers Crb and aPKC, the junctional marker Arm, and the basolateral marker Yrt. All panels show side views of the ectoderm or epidermis at the indicated stages. Epithelial cysts in cyst-compromised embryos are evident in stage-11, -13, and -15 embryos (arrowheads) but not at stage 10. Markers show normal subcellular distributions of apical markers in cysts, facing the lumen where cuticle will be secreted (see Fig. 1, C–E). Insets show triple-labeled cells with Crb (A) or aPKC (B) shown in blue. n = number of embryos analyzed. Scale bars, 10 µm; insets, 5 µm.