Blue and ultraviolet sensitive classes of photoreceptors in the Drosophila fruit fly compound eye. The eye consists of about 800 units (viz., ommatidia) that in turn are composed of eight neural photoreceptor cells together with twelve non-neural supporting cells (viz., bristle, cone and pigment). R8 is considered to be the ‘founder’ cell that specifies the other photoreceptor cells via a network of interacting molecules. Like R7, it is an inner photoreceptor cell while R1-R6 generate dim light-sensitive rhodopsin Rh1. The eye of the fly has provided important insights into developmental signalling processes as well as the specification of neural cell types.
See Boss (or bride of seven less), Cones and rods, Developmental genetics, Ras, Sevenless, Tyrosine kinase receptor/pathway