Fig. 1

PrPC expression in uninfected PrP knockout (PrPKO) and wild-type (WT) retina using D13 antibody. a, b In PrPKO retina, normal host PrP (PrPC) was not detected by immunofluorescent stain (red) or immunohistochemical stain (brown). However, photoreceptors in OS of PrPKO retina showed red autofluorescence, a common but variable artifact of immunofluorescence studies of retina. c, d In WT retina, PrPC was observed by both staining techniques in the OPL and IPL, and weaker levels were detected in the INL and IS. Scale bar in a = 20 µm. OS outer segment, IS inner segment, ONL outer nuclear layer, OPL outer plexiform layer, INL inner nuclear layer, IPL inner plexiform layer