Rod and cone degeneration in the rd mouse is p53 independent

PURPOSE: To determine whether p53 is required for the death of rod and cone photoreceptors in rd mice, a model of human retinitis pigmentosa, and/or f or the natural degeneration of inner nuclear layer (INL) cells in the devel oping retina. METHODS: Rod photoreceptor and INL apoptosis was assessed by TUNEL staining of mouse sagittal sections from post natal day (P) 10, 13, 15, 17, and 20 day p53+/+ and p53-/- rd retinas. Cone photoreceptor survival was measured by counting the total number of peanut agglutinin (PNA) positive cells in e ighty four 0.25 mm x 0.25 mm bins in each eye, distributed equally across t he four quadrants of whole mount retinas from 3 month old p53+/+ and p53-/- rd retinas. RESULTS: Both the kinetics of rod and INL cell death as well as the surviva l of cones were essentially unaffected by the absence of p53. CONCLUSIONS: Despite established links with retinal apoptosis, p53 is not e ssential for rod or cone cell degeneration in the rd mouse or for the elimi nation of bipolar and Muller cells during late retinal development.