Rhodopsin plays an essential structural role in Drosophila photoreceptor development

Null mutations of the Drosophila Rh1 rhodopsin gene, ninaE, result in developmental defects in the photosensitive membranes, the rhabdomeres, of compound eye photoreceptors R1-R6. In normal flies, Rh1 expression begins at about 78% of pupal life. At approximately 90% of pupal life, a specialized catacomb-like membrane architecture develops at the base of normal rhabdomeres. In ninaE null mutants, these catacombs do not form and developing rhabdomere membrane involutes into the cell as curtains of apposed plasma membrane. A filamentous cytoskeletal complex that includes F-actin and the unconventional myosin, NINAC, decorates the cytoplasmic surface of these curtains.