Fig. 7. Morphological analysis of sciatic nerves. Semi-thin sections of sciatic nerves of controls (A,B) and mutants (C,D). ß-galactosidase activity (labelling sensory axons in light blue) was detected in semi-sections, which were also counterstained with Alcian Blue. In B,D, red arrowheads, red arrows and black arrows indicate the unmyelinated sensory axons and the myelinated sensory and motor axons, respectively. The black arrowheads in D indicate the unsegregated sensory axons of small to large diameter. (E) Electron microscopy image of a mutant sciatic nerve transverse section on P21. Scale bar: 0.5 µm.