Fig. 2: VE-Cadherin⁺CD61⁺EPCR⁺ (V⁺61⁺E⁺) surface phenotype enriches for functional HSC precursors during the transition from HE to HSC in the AGM.

a Sorting by FACS of E9 (18-21 sp) AGM/P-Sp-derived cells based on the expression of CD61 and EPCR within the VE-Cadherin⁺ population (see also Supplementary Fig. 2). b Each population in a was co-cultured on AGM-EC, transplanted to lethally irradiated adult mice, and analyzed for donor-derived peripheral blood (PB) engraftment in primary (20 weeks) and secondary (16 weeks) recipients. The numbers above indicate the fraction of mice with multilineage engraftment in each group, designated by data points in red. (Similar results obtained in n = 1 independent experiment; source data are provided as a Source Data file). c Methodology for index sorting of single VE-Cadherin⁺EPCR⁺ (V⁺E⁺) cells for co-culture on AGM-EC and subsequent analysis to assess HSC potential by flow cytometry and transplantation. d Correlation of clonal HSC potential with surface expression of CD61, CD45, and CD41 on individual index-sorted V⁺E⁺ cells from E11 (40-42sp) AGM. HSC colony-forming cell (HSC CFC) (red) indicates the formation of a hematopoietic colony with HSC activity as detected by surface phenotype (VE-Cad^−/lowCD45⁺Gr1⁻F4/80⁻Sca1^hiEPCR^hi) and long-term (≥24 weeks) multilineage engraftment. (Source data are provided as a Source Data file). Non-HSC CFC (blue) indicates the formation of a hematopoietic colony lacking HSC phenotype and/or long-term engraftment. No colony (gray) indicates the absence of detectable hematopoietic cells following AGM-EC co-culture. (See also Supplementary Figs. 2–4).