Double immunostaining of EphA4 (redin B, C, E,F, H, I, K,L, N, and O) and BrdU (green in A, C,D, F, G, I,J, L, M, andO) in coronal plane of frozen sections of a stage 37 (E11) cerebellum that was pulsed with BrdU on E5. In all lobules, late-born cells colocalize to the EphA4 negative band,C, E, and to band A (or medial portion of band A) where a lower level of EphA4 immunostaining is detected (see Results). For technical reasons (see Material and Methods, BrdU labeling), lower EphA4 expression inband A of lobule VII is obscured in H and is better observed in a 20 μm adjacent section in Figure7H. P–R, Double immunostaining of EphA4 (red in Q and R) and BrdU (green in P andR) on E11 chick cerebellum that was pulsed with BrdU on E3. Early-born cells colocalize with EphA4-positive bands.A, B, C, D, and E refer to Purkinje cell bands labeled alphabetically from the midline. Roman numerals refer to cerebellar lobules. Scale bar, 100 μm.