Figure 1.

Zebrafish olig1 is expressed in the OL lineage. olig1 expression was revealed by in situ hybridization. A–C, Whole-mount dorsal view; anterior is to the top. Some cells in the diencephalon began to express olig1 at 48 hpf (A), and then olig1 expression extended posteriorly at 60 hpf (B). At 72 hpf, the expression domain expanded through the entire brain and spinal cord (C). D–R, Transverse sections through trunk; dorsal is to the top. In the spinal cord at 72 hpf, olig1 partly colocalized with olig2 in white matter (D–F, arrows) and partly with other OL lineage markers sox10 (G–I), mbp (J–L), mpz (M–O), and plp1b (P–R). sox10 and mbp were also expressed in the PNS (arrowheads). Scale bars: 20 μm.