In this paper we have determined that the primary role of the rod-specific transcription factor, Nr2e3, is to maintain cone genes transcriptionally silent within rods. We have identified two patterns of cone gene derepression in the rd7 mutant retina, in agreement with a previous report by Chen et al. [18]. The first pattern of derepression identified (type I) consists of ectopic expression of cone genes in the vast majority of cells in the ONL. These cells were also shown to coexpress all rod genes tested. Consistent with the hybrid pattern of gene expression in these cells, electron microscopic analysis revealed them to be morphologically intermediate between normal rods and cones.