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 Hmga2 and Ccnd1 when compared to radial glial cells (RGCs). RGCs display dynamic gene expression over time; for instance, early RGCs express higher levels of Hes5, and late RGCs show higher expression of Pou3f2. Interestingly, intermediate progenitor cell marker gene Eomes 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 Eomes-positive cells.

在哺乳动物新皮层中，投射神经元类型由相同的神经祖细胞池顺序生成。神经元类型规范如何与发育时间相关仍不清楚。为了确定神经祖细胞中的时间基因表达是否与神经元类型规范相关，我们对发育中的小鼠新皮层进行了单细胞 RNA 测序 (scRNA-Seq) 分析。与放射状胶质细胞 (RGC) 相比，我们发现了富含神经上皮细胞的基因，如Hmga2和Ccnd1。RGC 随时间显示动态基因表达；例如，早期 RGC 表达更高水平的Hes5，晚期 RGC 显示更高水平的Pou3f2。有趣的是，中间祖细胞标记基因Eomes在不同的发育阶段与已知的神经元身份基因在时间上共表达，但主要是在有丝分裂后的细胞中。我们的结果描绘了发育中的小鼠新皮层中神经祖细胞的多样性，并支持神经元同一性基因在Eomes阳性细胞中的转录明显。