Figure 3

Identification of neural progenitors for a second motor neuron lineage.A and B, the expression of neural progenitor markers hes6 and sox2 by UMAP. C, enriched markers in the radial glia compared to the pMN progenitors. D, enriched pathways of differential genes in radial glia and pMN progenitors. E, subclustering of the radial glia by UMAP. F, the expression of olig2 in radial glia subpopulations by UMAP. G, enriched markers of radial glia subpopulations. H, proliferation scores (G2M scores) of subpopulations in the radial glia. I, major enriched pathways in radial glia subpopulations. J, lineage inference analysis of subpopulations in the radial glia. K–M, the expression of motor neuronal markers in subpopulations of radial glia. N, singleR analysis between radial glia subpopulations and other representative cells. O, heatmaps showing gene expression in motor neurons and in subpopulations of radial glia. Selected genes were expressed in at least 60% of MN1 or MN2. P–R, olig2+ cells are sometimes colabeled with GFAP. Confocal images of whole-mount Tg(olig2:dsRed; gfap:GFP) embryos at 72 hpf, lateral view. Images from a single confocal slice. Notice that dsRed⁺ nuclei are surrounded by the GFP driven by the gfap promoter (arrows). Boxes a–d showing the enlarged images in the R. S, motor neuron projections were observed in Tg(gfap:GFP). Arrows denote the projections from the spinal cord to the periphery. Dorsal top, caudal left. The scale bar represents 50 μm in (R) and (S). The scale bar represents 10 μm in d. hpf, hour post fertilization; UMAP, Uniform Manifold Approximation and Projection.