In vitro differentiation of Gata2 and Ly6a reporter embryonic stem cells corresponds to in vivo waves of hematopoietic cell generation

In vivo hematopoietic generation occurs in waves of primitive and definitive cell emergence. Differentiation cultures of pluripotent embryonic stem cells (ESC) offer an accessible source of hematopoietic cells for blood-related research and therapeutic strategies. However, despite many approaches, it remains a goal to robustly generate hematopoietic progenitor and stem cells (HP/SC) in vitro from ESC. This is partly due to the inability to efficiently promote, enrich and/or molecularly-direct hematopoietic emergence. Here we use novel Gata2Venus (G2V) and Ly6a(SCA1)GFP (LG) reporter ESCs, derived from well-characterized mouse models of HP/SC emergence, to show that during in vitro differentiation they report emergent waves of primitive HPCs, definitive HPCs and B-lymphoid cell potential. These results, facilitated by enrichment of single and double reporter cells with HPC properties, demonstrate that in vitro ESC differentiation approximates the waves of hematopoietic cell generation found in vivo, thus raising possibilities for enrichment of rare ESC-derived HP/SCs.