This null allele disrupts the vitamin A metabolism in the retinal pigment epithelium, resulting in an absence of 11-cis-retinyl esters and an accumulation of all-trans-retinyl esters there. Homozygotes lack rhodopsin but not opsin and retinal rod and cone degeneration occurs, but no other organs requiring vitamin A were found grossly histologically altered. In homozygotes on a mixed B6;129 background cone cell degeneration is rapid, beginning around 2 weeks of age and reaching completion by 4 weeks of age. The rod degeneration is slower. At 7 weeks of age the rod photoreceptor outer segment is shorter, the discs are not as tightly packed as normal and appear more disorganized. At 15 days of age there are voids visible by electron microscopy that are visible by light microscopy. Slow degradation of the photoreceptor nuclei is also observed, with the nuclear layer thinned to 8-9 layers by 15 weeks of age, which decreased further to 7 layers at 28 weeks of age. The retinal pigment epithelium at 15 weeks of age shows numerous lipid inclusions. Consistent with the histological findings, the dark adapted ERG is severely diminished. On the mixed B6;129 background homozygotes were not found to display the retinal white spots that are found in Rpe65rd12 homozygotes on a C57BL/6J background so Dr Bo Chang created this C57BL/6J congenic Rpe65tm1Tmr strain for direct comparison, and white retinal spots are evident in this congenic by 3 months of age.

This null allele provides a model for Leber congenital amaurosis 2 and studies of the retinoid visual cycle.

Typically mice are recovered in 12-16 weeks. Contact Customer Service to place an order or for more information.

<a target="_blank" href="https://www.jax.org/jax-mice-and-services/customer-support" rel="noreferrer">Contact Customer Service</a> for more information.