Rod and cone degeneration in the rd mouse is p53 independent.
OBJECTIVE
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 for the natural degeneration of inner nuclear layer (INL) cells in the developing 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 eighty four 0.25 mm x 0.25 mm bins in each eye, distributed equally across the 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 survival of cones were essentially unaffected by the absence of p53.


CONCLUSIONS
Despite established links with retinal apoptosis, p53 is not essential for rod or cone cell degeneration in the rd mouse or for the elimination of bipolar and Muller cells during late retinal development.
Wu
J
J
Vision Science Research Program, Cellular and Molecular Division, Toronto Western Research Institute, University Health Network, Toronto, Canada.
Trogadis
J
J
Bremner
R
R
D000818:Animals; D017209:Apoptosis; D002452:Cell Count; D002470:Cell Survival; D017931:DNA Primers / Q000737:chemistry; D005838:Genotype; D007124:Immunoenzyme Techniques; D020287:In Situ Nick-End Labeling; D051379:Mice; D008810:Mice, Inbred C57BL; D008817:Mice, Mutant Strains; D019887:Peanut Agglutinin; D020419:Photoreceptor Cells, Vertebrate / Q000378:metabolism / Q000473:pathology*; D012160:Retina / Q000254:growth & development; D012174:Retinitis Pigmentosa / Q000378:metabolism / Q000473:pathology*; D016159:Tumor Suppressor Protein p53 / Q000502:physiology*
D017931:DNA Primers; D019887:Peanut Agglutinin; D016159:Tumor Suppressor Protein p53