Defects in cerebellar development in En1-Drp1KO mice. (A) Immunofluorescence of cerebellum (Cb) at P1 using anti-Drp1 antibodies. (B) H&E stains of sagittal sections of cerebella. (C) Area of cerebella in sagittal sections around the median line was determined (n = 3). (D and E) Sagittal cerebellar sections were immunostained using antibodies to Ki67 (D) or activated caspase-3 (E). (F) EM of PCs at P0. Arrows indicate mitochondria. Sagittal sections of cerebella are shown. (G) Quantitation of mitochondrial shape and size in PCs. (H) EM of granule cells (GC) in the external granular layer (EGL). Sagittal sections of cerebella are shown. (I) Immunofluorescence of sagittal cerebellar sections around the median line using anti-Car8 antibodies. PCL, PC layer. (D, F, and H) Boxed areas are enlarged in the corresponding panels below. *, P < 0.05. Error bars indicate mean ± SEM.