Figure 7.

Dependence of retinal degeneration on light and age. Flies were raised in twelve-hour day-night cycle (left column; labelled with black and white bar) or in complete darkness (right column; black bar) and aged for several days at 25°C. Time points shown: 3d, 0–3 days after hatching; 14d, 10–14 days after hatching. Enlargements of each 4 × 4 ommatida are shown to highlight the defects. A) Eyes of control flies: Note the regular architecture of ommatidia, which is independent of light and age. B) PKD-SE was overexpressed behind the morphogenetic furrow. In the light (left), rhabdomeres are elongated and sometimes fragmented or completely absent. In the dark (right) these phenotypes are less extreme but still detectable. They are largely independent of age. C) dsPKD was likewise induced in a light-dark cycle (left) and in the dark (right). Note degeneration of rhabdomeres in the light reared, 14 days old flies. The degeneration is less severe in younger flies or those kept in the dark. Genotypes are: A) gmr-Gal4/+; B) gmr-Gal4/PKD-SE^139-2; C) gmr-Gal4/+, UAS-dsPKD^114-5 /+. Scale bar, 10 μm.