Effects of homeobox genes on the differentiation of photoreceptor and nonphotoreceptor neurons.

Purpose: The homeobox genes Pax6 and Chx10 are diffusely expressed in proliferating, undifferentiated retina neuroepithelial cells. Distinct, topographically specific expression patterns emerge, however, as postmitotic cells become organized into layers. The hypothesis that the product of each gene may be necessary for the differentiation of particular nonphotoreceptor neuron subsets and that their absence may be required for progenitor cells to differentiate as photoreceptors was tested in this study.