Figure 2. Retinal changes 7 days after a single systemic administration of 60 mg/kg N-methyl-N-nitrosourea (MNU) to p53^−/−, p53^+/−, and p53^+/+ mice. In MNU-treated p53^−/−, p53^+/−, and p53^+/+ mice, the outer nuclear layer and photoreceptor layer disappeared in both the peripheral and central retina. Equivalent levels of severe retinal degeneration were detected in MNU-treated p53^−/−, p53^+/−, and p53^+/+ mice. GCL, ganglion cell layer; IPL, inner plexiform layer; INL, inner nuclear layer; OPL, outer plexiform layer; ONL, outer nuclear layer; PRL, photoreceptor cell layer; and PEL, pigment epithelial cell layer. The sections were stained with hematoxylin and eosin. The scale bar represents 70 μm.