We found that genes related with oligodendrocyte development were present in five non-neuronal clusters (Figure S3G). Transcription factors controlling oligodendrocyte maturation (OLIG1 and OLIG2) were present in only one of these clusters (OL). Two clusters display higher expression of astrocyte-related genes than oligodendrocyte-related genes (AS1-2). Interestingly, astrocytes (marked by S100B and GFAP) were derived from both hMGEOs and hCOs, suggesting that human MGE cells give rise to progenitors for astrocytes, which is consistent with the recent observation of astrocyte production in NKX2-1 expressing mouse ventral telencephalon (Minocha et al., 2015). One cluster that lacked both oligodendrocyte and astrocyte-related genes but expressed gliogenesis genes was annotated as glia progenitor cell (GPC).
