Figure 4.

DCC is required to prevent ectopic motor neuron migration. A series of netrin receptor mutant embryos were analyzed at E13.5 for ectopic MNs in the rostral half of the spinal cord. As in controls (A, n = 3), ectopias were not observed in Dscam (B, n = 3), Unc5C (C, n = 3), or Neogenin (D, n = 2) mutants. There were, however, ectopic MNs in DCC mutants (n = 4) positive both for Islet 1/2 (E) and HB9 (F). Quantified in (G). Scale bar in (F) is 50 μm. *indicates P < 0.05 by Tukey’s post hoc test.