Figure 5

Increased neurogenesis of VZ-derivatives in Sox9-null cerebellum. (A-B) Immunofluorescence staining on cerebellar sagittal sections showed an up-regulation of Calbindin expression in the Sox9 mutant with an ectopic expression domain close to the VZ (arrows). (C-D) More Foxp2⁺ cells could be found in the Sox9 mutant cerebellum and the spatial distribution of which closely mimicked the expression pattern of Calbindin (compared with B). (G) Quantification of Foxp2⁺ cells confirmed a 1.3 fold increase in the Purkinje cell populations, the surplus of which was predominantly localized outside the PCL at the vicinity of VZ. (E, F and H) The number of Pax2-expressing cells was also increased by about 30% in the Sox9-null cerebellum than in the control. Asterisks (***) indicate statistically significant difference of p-value < 0.0001 by the Student’s t-test. The error bars indicate standard deviations. Abbreviations: egl, external granular layer; vz, ventricular zone. Scale bars: A-C: 100 μm.