Figure 2.

Mislocalization of Nodal Complexes in Caspr Null and ΔC-Caspr-GFP/Caspr^−/− Mice

(A) Although most nodes are mature in WT nerves at P6 (see Figure 4), earlier stages of heminode fusion can be detected by immunofluorescence for either Nfasc186 or Nav (both nodal proteins) with Caspr and Neurofilament (NF).

(B) Immunofluorescence at P6 showed that complete disruption of the axoglial complex (Caspr^−/−) or removal of the Protein 4.1B binding site in Caspr (ΔC-Caspr-GFP/Caspr^−/−) abolished symmetrical heminode formation and resulted in a single nodal complex. Heminode formation was rescued with transgenic Caspr (Caspr-GFP/Caspr^−/−).

(C) Immunostaining at P6 showed that the mislocalized nodal complex in ΔC-Caspr-GFP/Caspr^−/− mice contained Nav, Nfasc186, βIV spectrin, and ankyrinG.

(D) Immunofluorescence at P6 for Nfasc186 and Nav in the absence of Protein 4.1B (4.1B^−/−) showed that the nodal complex was mislocalized.

The scale bars represent 5 μm. See also Figure S1.