Temporal expression of rod and cone opsins in embryonic goldfish retina predicts the spatial organization of the cone mosaic.

Abstract

The onset of opsin expression in goldfish retina follows a highly ordered spatio-temporal pattern. Early differentiation and regular spacing of the precocious rods was unexpected and suggested that they may play a role in cone mosaic patterning. The order of subsequent cone opsin expression was related to the relative positions of cone subtype in the mosaic, suggesting the possibility that inductive interactions among developing photoreceptors may be responsible for patterning the cone mosaic array.