Fig. 1. Generation and migration of oligodendrocyte precursor depends on the spinal cord region. (A) The spinal cord shows three distinct domains used in this study. The spinal cord was opened at the roof plate and cutting at the sulcus limitians generates dorsal explants. Ventral regions were then bisected into intermediate and ventral explants. (B,C) Dorsal explants from stage 29 chick embryos did not give rise to oligodendrocyte precursors after 3 days in culture, consistent with previous findings (Warf et al., 1991), although numerous axon bundles were seen. (D,E) Ventral and intermediate explants generated O4-positive oligodendrocyte precursors that differed in number and migrational distances. (F,G) Ventral explants generated higher numbers of oligodendrocyte precursors that migrated farther than those from intermediate explants. P<0.001. Scale bar: 250 µm.