(A–D) Knockdown of Nrp1 siRNA and Slit2 MO but not Nrp1 siRNA or Slit2 MO alone causes ectopic migration of motor neurons in the chick neural tube (arrowheads, D) (n > 80 sections in 6 embryos). (E–H) Sox10+ BC cells are intact in embryos in which Nrp1 and Slit2 are downregulated. (I, J) Quantification of % sections with ectopic motor neurons treated with Nrp1 siRNA, Sema3A (3A) siRNA and Slit2 MO (I), and semaphorin siRNAs and Slit2 MO (J). Error bars represent SEM. ***p < 0.001 vs. control; one-way ANOVA test, post hoc Tukey’s multiple comparison test (I); unpaired Student’s t-test (J); n.s., not significant. Scale bar: 50 μm