Fig. 1. Morphological alterations in the Ebf2 null cerebellum. (A-F) Nissl staining of cerebellar sections at different postnatal stages. Roman numerals indicate lobule numbers. At P20 (A,B), P30 (C,D), and P60 (E,F) the median region of the mutant cerebellum is sharply reduced (arrowheads in D,F). In B, note misfolding in the hemispheres. Foliation defects are evident in the vermis: lobules I-II and III are smaller (solid arrowheads in F), lobules IV and V are fused (white arrowhead in F). Lobules VIb and VII are malformed (arrows in F). (G) Mean number of PCs calculated in P15 wt versus mutant cerebella (n=3, ±s.e.m.). The value expresses the mean number of PCs/section in each series. In the mutant the number of PCs is 38% reduced. For details on procedures used in G, see Materials and methods. PM: paramedian lobule; Sim: simple lobule; MedDL: medial dorsolateral nucleus; PFl: paraflocculus; Fl: flocculus; IC: inferior colliculus. Scale bar: 500 µm.