Progenitor cell diversity in the developing mouse neocortex.

Abstract

In the mammalian neocortex, projection neuron types are sequentially generated by the same pool of neural progenitors. How neuron type specification is related to developmental timing remains unclear. To determine whether temporal gene expression in neural progenitors correlates with neuron type specification, we performed single-cell RNA sequencing (scRNA-Seq) analysis of the developing mouse neocortex. We uncovered neuroepithelial cell enriched genes such as <i>Hmga2</i> and <i>Ccnd1</i> when compared to radial glial cells (RGCs). RGCs display dynamic gene expression over time; for instance, early RGCs express higher levels of <i>Hes5</i>, and late RGCs show higher expression of <i>Pou3f2</i> Interestingly, intermediate progenitor cell marker gene <i>Eomes</i> coexpresses temporally with known neuronal identity genes at different developmental stages, though mostly in postmitotic cells. Our results delineate neural progenitor cell diversity in the developing mouse neocortex and support that neuronal identity genes are transcriptionally evident in <i>Eomes</i>-positive cells.