A congenic C57BL/6J rd1 mouse model for retinal degeneration research

Retinitis pigmentosa is an inherited retinal disease caused by thousands of mutations in over 100 different genes. The most widely used mouse model for retinitis pigmentosa has the retinal degeneration 1 (rd1) mutation in the Pde6b gene, which elicits rapid retinal degeneration and vision loss. A major limitation of these models is that these rd1 strains are not congenic, which prevents the use of appropriate controls. Furthermore, many strains have mutations in other genes which introduces genetic variability and may confound results. To address this issue, we backcrossed the rd1 allele from FVB mice onto a C57BL/6J genetic background over many generations, producing a C57BL/6J.Pde6b^rd1 strain that was confirmed to be congenic to C57BL/6J mice. We show that this strain recapitulates the electroretinogram and optomotor results expected for mouse strains containing the rd1 mutation. Examination of retinal structure in cross sections of eyes isolated from C57BL/6J.Pde6b^rd1 mice show a degree of thinning of the outer nuclear layer expected for a rd1 mutation, resulting in nearly complete loss of the outer nuclear layer by postnatal day 35. We anticipate that this C57BL/6J.Pde6b^rd1 strain could become an asset for the field of retinitis pigmentosa research.