Truncated radial glia as a common precursor in the late corticogenesis of gyrencephalic mammals

The diversity of neural stem cells is a hallmark of the cerebral cortex development in gyrencephalic mammals, such as Primates and Carnivora. Among them, ferrets are a good model for mechanistic studies. However, information on their neural progenitor cells (NPC), termed radial glia (RG), is limited. Here, we surveyed the temporal series of single-cell transcriptomes of progenitors regarding ferret corticogenesis and, despite the large timescale difference, found a conserved diversity and temporal trajectory between human and ferret NPC. We focused on truncated RG (tRG), a progenitor subtype previously described in humans. Results from time-lapse imaging in the ferret model suggest that tRG are generated from asymmetric apical divisions of RG sister cells. Moreover, the combination ofin silicoandin vivoanalyses identified that tRG differentiate into both ependymal and astrogenic cells. Via transcriptomic comparison, we predict that this is also the case in humans. Our findings suggest that tRG play a role in the formation of adult ventricles, thereby providing the architectural bases for brain expansion.