Figure 3.

Exogenous GFRα1 Enhances PC Migration in Cerebellar Explants

(A) Representative images of explants of cerebellum primordium from E12.5 wild-type (Gfra1^WT) and Gfra1 knockout (Gfra1^KO) embryos cultured in Matrigel for 4 days on a nanofiber surface and stained for the PC marker Lhx5. The border of the explant is indicated. Scale bar, 200 μm.

(B) Relative cumulative frequency of Lhx5⁺ cells exiting cerebellar explants from the indicated genotypes normalized to explant surface area. Gfra1^KO (red; n = 106 explants) versus Gfra1^WT (blue; n = 263) Kolmogorov–Smirnov test, p = 0.0003. Migration was restored in Gfra1^KO explants grown on a nanofiber surface coated with purified GFRα1-Fc protein (green; n = 129; Kolmogorov–Smirnov test, p < 0.0001 compared to Gfra1^KO on control surface).

(C) Relative cumulative frequency of Lhx5⁺ cells showing the effect of immobilized GFRα1-Fc on cerebellar explants from wild-type (Gfra1^WT) embryos. GFRα1-Fc (red; n = 229 explants) versus control (blue; n = 231 explants) Kolmogorov–Smirnov test, p = 0.0003.

(D) No effect of soluble (sol) GFRα1-Fc on PC migration (blue, n = 213 explants; red, n = 98 explants; Kolmogorov–Smirnov test, p > 0.05).

(E) Relative cumulative frequency of Lhx5⁺ cells exiting wild-type cerebellar explants growing on surface coated with GFRα2-Fc. The difference was not significant (n = 118 and 135 explants, respectively; Kolmogorov–Smirnov test, p > 0.05).

(F) No effect of coated GFRα2-Fc on PC migration in cerebellar explants from Gfra1^KO embryos (blue, n = 66 explants; red, n = 88 explants; green, n = 97 explants; Kolmogorov–Smirnov test, p = 0.817, red versus green curves).

(G) No effect of coated Fc fragment on PC migration in cerebellar explants from wild-type embryos (blue, n = X explants; red, n = X explants; Kolmogorov–Smirnov test, p > 0.05).