Elucidating photoreceptor gene function with in-vivo CRISPR knock-out perturbation assay.

Over the past two decades, considerable progress has been made in cataloguing genes and active chromatin elements in humans. However, despite these efforts, less than a quarter of genes have been assigned a function in the context of human disease, which limits our ability to interpret clinical genome sequencing results. In the field of inherited retinal diseases, 30-40% of cases remain genetically undiagnosed. This may be partially due to our limited understanding of the function of most retina-expressed genes, which prevents the correct interpretation of their sequence variations. In the effort of elucidating retinal gene function, we aimed at developing a protocol for in-vivo CRISPR-based gene knock-out perturbation in the mouse retina. This methodology can be useful to study retinal biology in health and disease, to investigate the effects of ablation of novel uncharacterized genes, and to study possible genetic modifiers of retinal phenotypes.