Fig. 3

Clinical and histological features of retinal degeneration in old Normande cows. a and b Eyes fundus from control RP1 Fs/Wt (a) and affected RP1 Fs/Fs (b) Normande cows. Arrows indicate hyperreflective areas and note the general reduction of the caliber of blood vessels in the affected animal. c and d Histological sections of the retina from the same control (c) and affected (d) animals. Note the total absence of inner and outer segments of photoreceptor cells and a marked thinning and disorganization of the outer nuclear layer confirming retinal degeneration in the Fs/Fs animal. (GCL ganglionic cells layer, IPL inner plexiform layer, INL inner nuclear layer, OPL outer plexiform layer, ONL outer nuclear layer, IS inner segment, OS outer segment. 5 µm sections of tissue embedded in paraffin and stained with HES. The choroid is not shown due to large artefactual gaps created by tissue preparation)