Figure 3

Neurofascin Functions in Oligodendrocytes to Regulate Myelin Targeting

(A) Real-time PCR analyses of the expression of nfascb, the myelin gene myrf, the neuronal genes rbfox3a (NeuN) and caspr in neuronal (N) and myelinating glial (MG) cells separated using FACS.

(B) Confocal images of Nfascb-GFP with cells counterlabelled with mRFP showing concentration of NfascB-GFP at the tips of myelin sheaths (b1-3), where paranodal junctions are localized. Scale bar, 5 μm (top panel) and 2.5 μm (b1-3).

(C and D) Confocal images of single oligodendrocytes expressing Nfascb-GFP in wild type (C) and nfascb^ue56 mutants (D). Cells expressing wild type NfascB-GFP never myelinate cell bodies, whether they are mutant or wild type. Scale bars, 10 μm.

(E–G) Analysis of myelination in mice lacking Neurofascin from oligodendrocytes.

(E and F) Confocal images of the dorsal horn where assessments for myelination of cell bodies was carried out in control (Nfasc^+/+) and Neurofascin mutants (Nfasc^−⁄−/Nfasc186), showing MBP in green, the neuronal marker NeuN in red, and DAPI to indicate nuclei in blue. Insets show single neurons, including an example of a myelinated cell body in the mutant. Scale bar, 50 μm.

(G) Quantitation of myelinated cell body number in controls and Nfasc^−⁄−/Nfasc186 mutant mice (wild type mean 0.29 ± 0.21 SD, 10 sections per mouse, n = 5 mice, Nfasc^−⁄−/Nfasc186 mean 6.51 ± 1.70 SD, 10 sections per mouse, n = 5 mice, p < 0.0001, t test).