Human basal radial glia morphotypes are transcriptionally distinct and exhibit different cell fate determination

Basal radial glia (bRG) are key neural progenitors driving human neocortical expansion. They exhibit remarkable morphological heterogeneity, yet the stability and functional significance of their distinct morphotypes remains unclear. Using human cortical brain organoids combined with long-term live imaging and morphology-resolved spatial transcriptomics (CellShape-seq), we show that bRG morphotypes display distinct morphodynamic behaviors, proliferative capacities and transcriptional profiles. While bifurcated bRG remodel extensively during mitosis to produce morphologically diverse progeny, multipolar cells are most morphologically flexible during interphase. Multipolar bRG further show the greatest proliferative capacity and the transcriptional signature related to progenitor state. Bifurcated bRG are least proliferative and are enriched for the multifunctional gene expression regulator YBX1. Pharmacological inhibition of YBX1 depletes bifurcated bRG, reduces neurogenesis, and promotes glial commitment. Our findings link progenitor morphology, gene expression and fate, providing a framework for understanding the cellular logic of human cortical development.