Cadm3Y170C mutant nerves exhibit abnormal axonal organization. Teased sciatic nerves were immunolabelled using antibodies to Kv1.2, NrCAM and Caspr, as indicated. (A and B) Abnormal (arrowheads) distribution of Kv1.2 potassium channels. The location of the internodes (IND) is marked in B and the nodes are marked by asterisks. (C) Mild abnormalities in Caspr (line marked by an arrowhead in lower left panel), as well as abnormal distribution of Caspr along the internodes (arrowheads in lower right panel). (D) Quantification of the number of sites containing abnormal Kv1 clusters in wild-type and mutant (knock-in) nerves. Number of sites is shown per 300 nodes; **P < 0.0001, unpaired t-test, n = 3, 300 nodes per mouse were counted, mean ± SD. (E) Kv1.2 abnormalities are present in the knock-in (left) but not in Cadm3 null mice (middle) and are similar (although less severe) than Cadm4 null mice (right). The location of the nodes is marked by asterisks. Scale bars = 20 μm (A, B, C left, D), 10 μm (C right).
