Fig. 1.

Evidence for cell lineage of the cortical tRG in the human brain. A Schematic diagram of the experimental design for this study (also see Materials and Methods). B Re-analysis of scRNA-Seq data from 3,355 frontal cortical EGFR⁺ cells at GW21-GW26 [35] revealed the molecular identity of cortical tRG and their progeny (PyN-IPCs, bMIPCs, OPCs, APCs, OBiN-IPCs and EP-ependymal cells). Note that pericytes and endothelial (Endo) cells also expressed EGFR. C tRGs and APCs expressed RGC general markers FABP7, HES1, SLC1A3, SOX2, and VIM. D, E EGFR⁺ASCL1⁺PAX6⁺ cortical tRGs generated EGFR⁺ASCL1⁺PAX6⁺EOMES⁺ PyN-IPCs. Note that very few NEUROD6⁺ immature PyNs expressed EGFR. F–I Cortical tRGs also generated EGFR⁺ASCL1⁺OLIG2⁺OLIG1⁺DLL3⁺ bMIPCs, which in turn gave rise to OPCs (H), APCs (C, G) and OBiN-IPCs (I) (Slingshot unsupervised pseudo-time analysis in F). Note that PDGFRA was also expressed in a subpopulation of bMIPCs and APCs (H). Also note that OBiN-IPCs expressed GAD2 earlier than SP8 and Sp9 (I).