Figure 6: The emergence of fetal haematopoiesis after day 14.

(a) Heatmap shows temporal upregulation of markers associated with endothelial and haematopoietic cells in CD34⁺ isolated cells on day 10. (b) Black arrow: endothelial-like cell tube embedded in hepatocyte-like cells and filled with CD34⁺ cells. (c) Immunostaining shows expression of CD45 and HG. HG, pan-haemoglobin. Scale bar, 200 μm. (d) Microarray analysis shows haemoglobin γ expression is strongly upregulated by day 15. The Greek letters are representative of different types of globin chain of human haemoglobin expressed at different developmental stages²⁵. Scale bar, 200 μm. (e) Development of TAL1⁺ CD43⁺ cells among CD34+ population on day 8. (f) Left: close-up of a CD34⁺ tube-like structure covered by pericyte-like cells (NES⁺) that contains CD45⁺ haematopoietic-like cells on day 17. Scale bar, 200 μm. (g) Multipotency of isolated CD34⁺ population assessed by the Methocult CFU assay, showing generation of (h) erythrocyte (BFU-E) (i) granulocyte, macrophage (GM) (j) macrophage (M), and (k) granulocyte, erythrocyte, monocyte, megakaryocyte (GEMM) multicellular colonies. Scale bars in h–k, 100 μm. Data are mean±s.e.m. and representative of at least three cultures per group.