Fig. 5. Amphiphysin is localized to the apical membrane before rhabdomere formation in photoreceptor neurons. Amph protein (green) and F-actin (red) are shown in pupal photoreceptor neurons (A-F) or in adult eyes (G-I). Each image represents a single confocal section of a z-series. (A-C) Twenty-four hours APF, only actin accumulates at the apical surface of the photoreceptor cells, whereas Amph is found throughout the cell. (D-F) Forty-eight hours APF, Amph accumulates on the apical surface of the photoreceptor cells, where the rhabdomeres will develop. There is some overlap between F-actin and Amph, but F-actin becomes tightly colocalized with Amph only at 55 hours APF (see Fig. 7F). (G-I) In the adult eye, F-actin (red) strongly labels the rhabdomere membrane, whereas Amph (green) is specifically expressed in the lens-secreting cone cells above the rhabdomeres (arrows). Amph expression is also found in cells of the adult head.