Figure 1. Structural appearance of the archival tissue sections from which the plastic-embedded tissue blocks were used for DNA extraction. Sections were stained with paraphenylenediamine (PPD; A, C, D) or azure II/methylene blue (B). A: A corneal section from dog CLF4 affected with mucopolysaccharidosis VII shows the typical vacuolated inclusions in the stromal keratocytes and corneal endothelial cells [16]. B: A mid-peripheral retinal section from prcd-affected dog CLF1 shows disorganization of the photoreceptor layer and ~50% reduction in outer nuclear layer thickness [17]. C, D: Panels show images of the far peripheral (C) retina of normal nonhuman primate MR1 and the photoreceptor outer segment–retinal pigment epithelial interface of the mid-peripheral retina (D).