Division of Developmental Neuroscience, Tohoku University Graduate School of Medicine, Miyagi, Japan.
Dev Dyn. 2013 Dec;242(12):1442-53. doi: 10.1002/dvdy.24035. Epub 2013 Oct 7.
Differentiation of granule cells (GCs) begins from late embryonic stage in the developing dentate gyrus (DG). Migration of the neurogenic stem cells and progenitors in the developing DG makes understanding of the DG morphogenesis difficult. The proliferative area in the developing DG was divided into the three germinal matrices (GMs). However, the stage of the progenitor cells in each GM along the GC differentiation process is not clear.
Here, we extensively compared expression of neurogenic transcription factors (TFs) of which sequential expression in the neocortical development and the adult DG neurogenesis was reported. The GC differentiation marked by Prox1 expression takes place from embryonic day 16.5 in the tertiary GM. Although neurogenesis in each GM basically proceeds along the radial axis of the forming GC layer, cells expressing stem cell markers were observed intermingling with NeuroD/Prox1 expressing differentiated cells in the tertiary GM at postnatal day 5, and gradually restricted in the subgranular zone as the development went on.
We describe expression pattern of neurogenic TFs during DG development, which suggests conserved sequential expression of TFs in the GC lineage, and spatiotemporal relationships of GC differentiation and DG morphogenesis during embryonic and early postnatal periods.
颗粒细胞（GCs）的分化始于发育中的齿状回（DG）的晚期胚胎期。神经发生干细胞和祖细胞在发育中的 DG 中的迁移使得 DG 形态发生的理解变得困难。发育中的 DG 的增殖区被分为三个生发基质（GMs）。然而，每个 GM 中的祖细胞在 GC 分化过程中的阶段尚不清楚。
在这里，我们广泛比较了神经发生转录因子（TFs）的表达，这些 TFs 的表达在皮质发育和成年 DG 神经发生中均有报道。由 Prox1 表达标记的 GC 分化发生在胚胎第 16.5 天的三级 GM 中。尽管每个 GM 中的神经发生基本上沿着形成的 GC 层的放射轴进行，但在出生后第 5 天的三级 GM 中观察到表达干细胞标志物的细胞与表达 NeuroD/Prox1 的分化细胞混合，并且随着发育的进行逐渐局限于颗粒下层。
我们描述了 DG 发育过程中神经发生 TFs 的表达模式，这表明 GC 谱系中 TFs 的表达具有保守的顺序，以及胚胎期和出生后早期 GC 分化和 DG 形态发生的时空关系。
