Immunostaining for protein kinase C in wild-type (Cx36 +/+) and homozygous knock-out (Cx36 −/−) retina. Immunolabeling for protein kinase C displays no differences for Cx36 +/+ (A) and Cx36 −/− (B) retinas. In both types of animals, rod bipolar cells, few amacrine cells, and some outer segments of photoreceptor cells are labeled. Corresponding Nomarski images are shown on the left. Scale bars, 50 μm.