Comprehensive analysis of photoreceptor gene expression and the identification of candidate retinal disease genes

To identify the full set of genes expressed by mammalian rods, we conducted serial analysis of gene expression (SAGE) by using libraries generated fro m mature and developing mouse retina. We identified 264 uncharacterized gen es that were specific to or highly enriched in rods. Nearly half of all clo ned human retinal disease genes are selectively expressed in rod photorecep tors. In silico mapping of the human orthologs of genes identified in our s creen revealed that 86 map within intervals containing uncloned retinal dis ease genes, representing 37 different loci. We expect these data will allow identification of many disease genes, and that this approach may be useful for cloning genes involved in classes of disease where cell type-specific expression of disease genes is observed.