Figure 2

pattern of S100B gene expression in the cerebellum and inferior colliculus before midline fusion of the cerebellar plates (E13.5). A: lower power confocal image of the Cb primordium, illustrating the strong EGFP signal present near the MHB (red box) in a parasagittal section. B: zooming on the boxed area in A reveals the high level of S100B/EGFP colocalisation at the single cell level. C: near the MHB, and on coronal sections, EGFP tags a stretch of neuroepithelial cells approx. 300 μM in width, emitting thin processes towards the pial surface (arrowheads). The red dotted lines represent the approximate planes of sections D and F. The glial scaffold (boxed area) is entirely (D, E) or only partially visible (F), depending on how close to the midline is the plane of section. E: higher magnification of the boxed area in (D) illustrating the pattern of EGFP expression near the midline: both the S-shaped radial glial scaffold of the Cb, and the abutting IC neuroepithelium, are strongly labeled.