Diversity of Cortical Progenitors Directs Neuronal Layer Formation and Regional Glial Patterning

How distinct cortical progenitor types and their temporal differences influence neuronal and glial development remains a key question in neurobiology. While Radial Glial Cells (RGCs) are well-established as Neural Progenitors (NPCs), NG2+NPCs have emerged as contributors with unique characteristics. Here, we combined in utero electroporation, lineage tracing and transcriptomic profiling to compare lineage outputs of NG2+ and GFAP+NPCs in the developing mouse cortex. Both generate neurons and glia, but with partially distinct patterns in lineage output, spatial distribution, and fate bias. NG2+NPCs undergo an early neurogenic phase followed by glial differentiation, producing glia with laminar distribution biases. In contrast, GFAP+NPCs sustain neurogenesis longer, producing a broader range of neurons and more constant glia during development. Our findings highlight the contribution of progenitor identity and temporal differences to distinct, partially overlapping lineage trajectories, supporting a model in which fate potential and timing co-regulate the spatial and laminar organization of cortical cell types. Overall design: Bulk RNA-seq of NG2+ and GFAP+FACS-isolated cells at E14, after targeting at E12 by IUE using the StarTrack method.