Fig. 2. Ascl1-expressing cells give rise to neurons and oligodendrocytes. (A) GFP fluorescence in a whole-mount E11.5 embryo from the Ascl1-GIC transgenic line. Inset is a cross section showing expression in the sympathetic ganglia. (B-D') X-gal staining of Ascl1-GIC;R26R-lacZ E10.5, 11.5 and 12.5 embryos. Arrow in B indicates barely detectable X-gal staining in the sympathetic ganglia. (C',D') Vibratome sections through the neural tubes of embryos shown in C-D. (E-J) mRNA in situ hybridization on cross sections of E11.5 embryos with Ascl1 (E,G,I) or Cre (F,H,J) probes. (K) X-gal staining of a P30 spinal cord from an Ascl1-GIC;R26R-lacZ transgenic mouse showing labeled cells in gray and white matter. (L-O) Immunofluorescence for YFP (green) in P14 Ascl1-GIC;R26R-YFP transgenic spinal cords double-labeled in red with a marker for neurons (L, NeuN), oligodendrocytes (M, Olig2; N, APC) or astrocytes (O, GFAP). The images are from the dorsal horn gray matter regions (L and right of dotted line in M), or white matter region (left of dotted line in M,N,O). Note that YFP co-labels (yellow) with neuronal and oligodendrocyte markers (arrowheads in L-N) but not the astrocyte marker (O). di, diencephalon; dnt, dorsal neural tube; ent, enteric neurons; hb, hindbrain; mes, mesencephalon; sym, sympathetic neurons; vt, ventral telencephalon.