Figure 5.

CD131 is a marker of Megakaryocyte and Erythroid Progenitors (MEP) in the yolk sac

(A) MA-plot of the MEP cluster comparing E9.5 to E10.5 cells. The genes that are differentially expressed with FDR <1% are shown as black dots, and the names of the genes with FDR <1% and logFC >0.9 are shown. Arrow points to Csf2rb.

(B) Upper panel, UMAP visualization of the expression of Csf2rb. Lower panel, violin plot representation with boxplots of Csf2rb expression in all hematopoietic clusters.

(C) Representative contour plots showing cytometric analysis of CD131⁺ cells among YS Kit⁺ CD41⁺ cells at E9.5 and E10.5. At least two independent litters analyzed per time point.

(D) Quantification of the number of CD131⁺ cells per YS at E9.5 and E10.5. n = 15 and 11 at E9.5 and E10.5, respectively. Bars represent mean$\pm$ SEM.

(E) Pie chart indicating the proportion of CD131⁺ cells among A–D progenitor subsets.

(F) Expression of Gata1-mCherry and Pu.1-YFP among E9.5 and E10.5 YS CD131⁺ progenitors. n = 9 and 3 at E9.5 and E10.5, respectively.

(G) Colony forming units (CFU-C) assays of sorted CD131⁺ progenitors compared to population A and analyzed 12 days after. Cloning efficiency (left) and frequency of colony types (Mk, megakaryocyte; E, erythroid; E-Mk, E and Mk; Gr1, granulocytes; MF, macrophages; Myeloid, macrophages and granulocytes; EMP, mixed colonies) (right); mean $\pm$ SEM Four technical replicates of one pooled litter. Please also see Figure S5.