Figure 3.

Deficient remyelination of regenerated axons in erbin^−/− mice on day 20 after nerve injury. Shown are representative electron micrographs and g-ratios of respective segments of injured sciatic nerves of indicated genotypes on day 20 after injury. A, B, P2-3 segments. C, D, D2-3 segments. E, F, D4-5 segments. Open arrowheads indicate naked axons with a diameter equal to or larger than 1 μm. Scale bar, 5 μm. The averaged g-ratio was presented as means ± SEM. n ≥ 20 EM images of each mouse, three mice per genotype. ***p < 0.001. G, Fewer axons were myelinated in regenerating nerves of erbin^−/− mice. Scored were axons from over 20 EM images per mouse, three mice per genotype in an area of 0.01 mm². H, Increased number of unmyelinated axons with diameters equal to or larger than 1 μm in injured erbin^−/− sciatic nerves. Axons were scored as in G. **p < 0.01. I, Reduced MBP levels in distal segments of injured sciatic nerves in erbin^−/− mice. Proximal and distal segments were isolated from injured sciatic nerves of indicated genotypes on days 5 and 20 after injury, and subjected to Western blotting with MBP antibody and α-tubulin (to indicate equal loading). J, Quantitative analyses of data in I. n = 3. **p < 0.01, compared with wild type; ^##p < 0.01, compared with data of distal segments on day 5. P, Proximal; D, distal.