Figure 5.
Commissural axon phenotypes of Wnt1–Cre;Ext1flox/flox mice. mt, Wnt1–Cre;Ext1flox/flox; wt, control littermate. A–D, Transverse sections of E11.5 spinal cords stained with HE. E–H, Transverse sections of E11.5 spinal cords stained with anti-NF antibody. I–L, Transverse sections of E11.5 spinal cords stained with anti-TAG-1 antibody. Note that the ventral commissure (vc) is greatly reduced (D, H, L; see also the results of quantitative analysis in M–O). Arrowheads in E indicate ventrally directed commissural projection in the wild-type spinal cord, which is disorganized and reduced in mutants (F). Misrouted commissural axons projecting around and into the motor column are consistently observed in mutants (arrows in J). Scale bars, 100 μm.