Fig. 1. Cerebellar phenotype of Rb and Rb/p107 compound mutant mice at P15. Gross appearance of the cerebellum of wild type (A) and mutant (B-D) mice at postnatal day 15. Note the reduced size of the double mutant vermis. (E-H) Hematoxylin and Eosin stained median sagittal sections through the cerebellum of En2cre; Rb^LoxP/LoxP mice (n=3) (F) show preserved foliation, but slight reduction of the vermis size and retarded migration of granule cells (inset, arrows indicate EGL thickness), when compared with a wild-type littermate (n=3) (E). A similar, but more pronounced phenotype was observed in the cerebella of Rb/p107 double mutant mice (p107^+/-; n=9, p107^-/-; n=3) (G,H). Scale bar: 1 mm (100 µm in insets).