Supplementary MaterialsSupplementary Information Supplementary Figures 1-18, Supplementary Tables 1-3 and Supplementary Recommendations. from N = 3, 23, and 10 single IPs from E11, 14, and 16, respectively. FDR 0.1; E11 vs. E14 or E14 vs. E16 |Log Fold| 2.5. Since there are a few E11 IP samples (N = 3), many temporal-axis genes in Fig. 3 are not included in this list because of their FDR values. MS Excel spreadsheet. ncomms11349-s3.xlsx (54K) GUID:?C3945460-90A5-4DF3-BADC-441961503560 Abstract During cerebral development, many types of neurons are sequentially generated by self-renewing progenitor cells called apical progenitors (APs). Temporal changes in (S)-Willardiine AP identity are thought to be responsible for neuronal diversity; however, the mechanisms underlying such changes remain largely unknown. Here we (S)-Willardiine perform single-cell transcriptome analysis of individual progenitors at different developmental stages, and identify a subset of genes whose expression changes over time but is impartial of differentiation status. Surprisingly, the pattern of changes in the expression of such temporal-axis genes in APs is usually unaffected by cell-cycle arrest. Consistent with this, transient cell-cycle arrest of APs does not prevent descendant neurons from acquiring their correct laminar fates. Analysis of cultured APs discloses that transitions in AP gene expression are driven by both cell-intrinsic and -extrinsic mechanisms. These results suggest that the timing mechanisms controlling AP temporal identity function independently of cell-cycle progression and Notch activation mode. The functional business of the brain requires the ordered generation of large numbers of diverse neurons and glia during development. The size and diversity of neural cell populations rely on the spatial and temporal diversity of progenitor cells. In mammalian cerebral cortex, self-renewing progenitor cells are formed by elongation of neuroepithelial cells, and Elf2 repeated divisions at the apical surface of the ventricular zone (VZ) (S)-Willardiine generate a stratified neuronal business (these cells are thus termed apical progenitors (APs) or radial glial cells)1. Over time, these neural progenitor cells undergo temporal progression with respect to two properties (Fig. 1a). The first is the decision whether divisions are purely proliferative (expansive) or not. APs initially undergo proliferative divisions that generate two APs, and subsequently shift into a differentiating mode in which divisions give rise to non-AP cells, such as neurons2,3 or lineage-restricted intermediate progenitors (IPs)1,4. In the second, APs progressively change the fates of their differentiating progeny; deep-layer neuronsupper-layer neuronsglia1,5. The mechanisms underlying temporal patterns in neural progenitors are less well comprehended than those involved in the spatial patterning of these cells. Open in a separate window Physique 1 (S)-Willardiine Classification of cortical progenitor cells.(a) Scheme of mammalian cerebral development. Before onset of neurogenesis, APs (apical progenitor cells, neuroepithelial cells (NEs) at this stage) undergo proliferative symmetric division. After onset of neurogenesis, APs overtime undergo temporal progression with respect to two properties: division mode (proliferative versus neurogenic) and the fates of their differentiating progeny (deep-layer neurons versus upper-layer neurons). A, anterior; P, posterior; D, dorsal; V, ventral; IP, intermediate progenitor cell. (bCe) E14-based hierarchical clustering analysis of single-cell cDNA classifies E11- and E16-derived cortical progenitor cells. Clustering dendrograms show the results from the SigABC genes. In the dendrograms, each label represents a single cell, and the label colour indicates the cluster where it belongs. The values in red at the branches are AU (approximately unbiased) values (%). The horizontal branch length represents the degree of dissimilarity in gene (S)-Willardiine expression among the samples. See also Supplementary Figs 1C4. The transition of AP division mode from proliferative (symmetric) into differentiating (asymmetric) is not synchronized across the cerebral progenitor populace. This shift initially takes place sporadically, and then progressively propagates into the entire brain with different timing. Cell-intrinsic programs and extrinsic environmental signals6,7 control these alterations in the division mode of APs1,8. Notch signalling is essential for progenitor self-renewal in both the proliferative and the neurogenic.