Fig. 2. Ebf gene expression in the embryonic and postnatal wt cerebellum. Non-radioactive in situ hybridization on adjacent 7 µm frontal sections of the embryonic (A-G) and postnatal hemicerebellum (H-J). At E12.5 (A-C) Ebf2 expression is restricted to a thin subventricular portion of the cortical transitory zone (ctz), while Ebf1 and Ebf3 are expressed throughout the ctz. At this stage Ebf2 is the only member of the family to be strongly expressed in the median region of the cerebellar primordium (arrow in B) and in the nuclear transitory zone (ntz). At E17.5, the nested expression of Ebf2, Ebf3 and Ebf1 (D-F) is compared with the distribution of ROR (G), a global PC-specific marker. In the paramedian region, all Ebf genes are expressed, while more laterally some groups of cells are only positive for Ebf1 (white arrows) or for Ebf1 and Ebf3 (black arrows). At P3 the Ebf2 transcript is detectable in a subset of PCs while Ebf1 and Ebf3 are expressed in the majority of PCs. Ebf3 is also expressed in the external granular layer and in the DCN. f: fastigial nucleus; i: interpositus nucleus; d: dentate nucleus; ctz: cortical transitory zone; ntz: nuclear transitory zone; egl: external granular layer; pcl: PC layer. Scale bars: in G, 50 µm for A-C; 100 µm for D-G; in J, 200 µm for H-J.