Drosophila NinaB and NinaD Act Outside of Retina to Produce Rhodopsin Chromophore

The Drosophila ninaB gene encodes a β,β-carotene-15,15′-oxygenase responsible for the centric cleavage of β-carotene that produces the retinal chromophore of rhodopsin. The ninaD gene encodes a membrane receptor required for efficient use of β-carotene. Despite their importance to the synthesis of visual pigment, we show that these genes are not active in the retina. Mosaic analysis shows that ninaB and ninaD are not required in the retina, and...