Fig 1: Comparisons with available sc/snRNA-seq cerebellar data sets clarifies the nature of A+/G+ and A-/G+ precursors. Heatmaps show the average gene expression for Atp1b2, Npy and genes found to be shared by A+/G+ or A-/G+ cells and distinct subpopulations of astrocytes/astrocyte progenitors at P0 (a), P7 (b) or P60 (Adult, c) (values were obtained from the sc/snRNA-seq data sets). A-/G+ cells shared genes with the BG subpopulations and with the P0 neurogenic subpopulation, while A+/G+ cells showed genes in common with the sole parenchymal astrocyte subpopulation at all stages analyzed. P3 cerebellar sections were stained with candidate markers specific for A-/G+ (d–g) and A+/G+ (h,i) cells. GRIA1 (d), NPY (e), and MYBPC1 (f) were confirmed to be enriched in A-/G+ BG progenitors in the PCL and in the PWM (arrow in g) compared to A+/G+ cells (arrowheads in g), while AGT (h) and SLC6A11 (i) were specifically expressed in A+/G+ progenitors in the PWM. The astroglial identity was validated using an intrinsic GFP expressed under the control of the hGFAP promoter (d–g,i) or by GFAP staining (h) Scale bars: 20 µm. BG, Bergmann glia; GL, granular cell layer; ML, molecular layer; PCL, Purkinje cell layer; PWM, prospective white matter