MYRF is a gene that regulates the development and function of the retinal pigmented epithelium (RPE), which play an important role in maintaining photoreceptor structure and function. Mutations in patients have been implicated in eye size disorders, particularly causing a small, but structurally normal eye. We have utilized a molecular technique, single cell RNA sequencing, to investigate how loss of Myrf specifically in the RPE in a mouse model impacts downstream gene expression at three developmental timepoints and used this information to define the role of Myrf in development. Our work identified key cytoskeletal structural genes specific to the RPE, Ermn and Upk3b, and a gene important for the cell survival, Sox10, as critical targets of Myrf. In addition, we have identified and confirmed that the TGFbeta signaling pathway is dysregulated when Myrf is lost during development. This pathway is particularly relevant in RPE health and eye growth. Our electron microscopy and histologic analyses also confirm a defect in RPE structure and function. We place MYRF within a hierarchy of genes involved in RPE development and introduce novel candidate genes for further study as retinal degeneration and nanophthalmos candidate genes.
