Fig. 2: Molecular characteristics and heterogeneity of pituitary stem cells.

a DEGs between the stem cells and the differentiated endocrine cells shown by a z-scored heatmap. DEC: differentiated endocrine cells, which include the progenitor or precursor cells. b Bar plots showing differentially enriched KEGG pathways between the stem cells and the DEC detected by GSEA. Representative genes in each pathway are shown. Nominal P values are determined by two-sided Kolmogorov-Smirnov Test and adjusted by FDR. c Bar plots showing the stages of three subtypes of the stem cells. The Stem1 are mainly derived from the early stages (7 to 10 weeks), and the Stem3 cells are mainly derived from the late stages (19 to 25 weeks). Color: weeks postfertilization. d Violin plots of representative DEGs between the Stem1 and Stem3 cells. e Immunofluorescence staining for SOX2 and ASCL1 in the 8- and 23-week human fetal pituitaries. Triangles indicate representative cells coexpressing both genes. Scale bar, 50 μm. f The CC cluster are composed of different cell subtypes. The upper panel shows the average expression levels of the S and G2/M phase genes, and representative cell type markers. CC1 and CC2 are SOX2-positive stem cells with CC1 and CC2 being the S and G2/M phase, respectively. CC3 are non-stem cells expressing POU1F1, TBX19 or GATA2. The lower panel shows the proportions of the cycling to all stem cells as a function of weeks postfertilization. Data are presented as mean ± SEM. g Immunofluorescence staining of SOX2 and Ki67 in the 8-, 17- and 23-week human fetal pituitaries (left). Triangles indicate representative costaining cells. The right panel shows the ratios of double-positive and SOX2-positive cells in each sample (n ≥ 2). p-Value is determined by two-sided Wilcoxon test (*P = 0.023 which is less than 0.05, **P = 0.0024 which is less than 0.01). Data are presented as mean ± SEM. Scale bar, 50 μm.