Fig. 3. cdi expression pattern in the eye imaginal disc. (A-D) Cdi pattern (red) of a disc co-stained with prospero (green). The confocal image was captured at the level of the R7 cells to discriminate from the prospero-stained cone cells. Upper panels: cross-section. Lower panels: transverse section. Arrowheads point to the localization of R7 cells. The merged figure in A also shows nuclear staining with Sytox-green (blue) to show distribution of nuclei. Note that in the transverse XZ sections (lower panels) the localization of Cdi is more abundant in the apical region of the epithelium (top). (E-G) Co-localization of F-actin (green) and Cdi (red) in the apical constrictions. Arrowheads point to apical constrictions. Upper panels: optical section taken through the most apical domain of the eye disc. Lower panels: transverse sections. (H-J) High magnification of an ommatidium of the previous image, showing Cdi (red) in the F-actin enriched apical constriction (green). (K) High magnification of a transverse section of a pupal photoreceptor to show cytoplasmic localization of Cdi. Apical: top. Arrowhead points to the nucleus. (L-M) Two confocal planes of developing ommatidia of a cdi^BA01 early pupal disc stained with anti ß-galactosidase. Labeling is extensive throughout the ommatidial cells. Bars, 10 µm.