Timing and location of rhodopsin expression in newly born rod photoreceptors in the adult teleost retina.

Labeling of newly divided retinal cells with bromodeoxyuridine (BrdU) and a rhodopsin mRNA probe revealed that rhodopsin is first expressed by new rod photoreceptors 2 days after cell birth in an adult cichlid fish. Most new cells that expressed rhodopsin had nuclei located in the vitreal half of the outer nuclear layer (ONL), lending further support to the hypothesis that movement from scleral to vitreal ONL is associated with rod differentiation.