Fig. 2.

Neural tube closure and cerebellar granule cell migration depend on the GAP domain of Plexin-B2. (A) (Upper) Scanning electron microscopy pictures of E9.5 embryos. Arrow points to nonfused neural head folds. (Lower) Pictures of E15.5 embryos. Arrow points to the open cephalic neural tube (exencephaly). (Scale bars, 200 µm in Upper, 3 mm in Lower.) (B) (Upper) Nissl staining of adult cerebella. (Lower) Magnification of the boxed areas in Upper. Arrows point to clusters of ectopic granule cells. (Scale bar, 300 µm.)