Fig. 5. Nrp1 controls the onset of migration in an integrin-dependent manner.

(A to D) Nrp1 regulates migration onset downstream of Zeb2. (A) Littermate Zeb2^fl/fl animals were in utero electroporated at E14.5 with GFP, shScr, shNrp1, or Cre as indicated. Selected clips from the 50-hour time-lapse movie are shown. (B) Percentage of GFP⁺ cells starting migration during the indicated time windows. None = cells that do not initiate migration during imaging. N = 3 animals per condition. Two-way ANOVA with Bonferroni post hoc tests. (C) Proportion of multipolar GFP⁺ cells at different time points. N = 29 cells, 3 brains for WT; 33 cells, 3 brains for KO; and 25 cells, 3 brains KO + shNrp1. (D) Speed of radial migration. N = 9 WT + shScr, 9 KO + shScr, and 19 KO + shNrp1. One-way ANOVA (Kruskal-Wallis) with Dunn’s multiple comparison test. (E to G) Nrp1 induces laminar displacement through integrins. (E) WT animals were in utero electroporated at E14.5 with an internal ribosomal entry site–driven GFP construct, the same construct containing Nrp1 or with ItgB1DN as indicated. (F) GFP⁺ neurons in brain sections at E18.5. Scale bar, 100 μm. (G) Laminar distribution of GFP⁺ neurons. N = 7 control WT, 7 WT + Nrp1, and 9 WT + Nrp1 + ItgB1DN animals.