FIGURE 3.

Progressive retinal degeneration in P23H/+ mice. A, plastic sections of retinas from WT (+/+), heterozygous (P23H/+), and homozygous (P23H/P23H) mice of differing PND ages. Sections were stained with toluidine blue. OS, outer segment; IS, inner segment; ONL, outer nuclear layer; INL, inner nuclear layer; and GC/NFL, ganglion cell/nerve fiber layer. Arrows represent surviving rod nuclei in a homozygous P23H/P23H mouse. B, data showing the number of nuclei per column in genetically different mice. Cryosections from WT, P23H/+, and P23H/P23H mice of differing PND ages were used for quantification. Data were derived from three eyes of three or five eyes of five mice. P23H/+ mice show age-dependent progressive retina degeneration, which is more severe in the ventral retina compared with the dorsal retina. P23H/P23H mice lost most of their photoreceptor cells by PND 63.