Statistical analysis of recoverin-labeled vertical photoreceptor cell rows. No significant difference is seen between WT control, KO control, and KO hypo retinas. Significantly fewer ONL cell rows are found in WT hypo specimens compared to KO hypo retinas as well as corresponding controls (P < 0.001). Error bars SEM. *P < 0.05; **P < 0.01; ***P < 0.001.