Murine yolk sac and bone marrow hematopoietic cells with high proliferative potential display different capacities for producing colony-forming cellsex vivo

Increasing evidence suggests that hematopoietic stern and progenitor cells from embryonic and fetal tissues demonstrate proliferative capacities great er than cells isolated from adult hematopoietic tissues. Few studies have e xplored the organization of the high proliferative potential hematopoietic progenitor hierarchy in the murine yolk sac. We have demonstrated the appea rance of high proliferative potential colony-forming cells (HPP-CFC) in the yolk sac as early as embryonic day 8 (E8). Yolk sac HPP-CFC colony size an d differentiated cellular composition were similar to adult marrow HPP-CFC. The frequency of yolk sac HPP-CFC at E11 was greater than HPP-CFC frequenc y in the adult marrow. Replating of primary yolk sac HPP-CFC resulted in si gnificantly greater HPP-CFC and multipotent progenitors than replated adult marrow primary HPP-CFC. Similar results were obtained when AA4.1-expressin g yolk sec and adult marrow cells that bind wheat germ agglutinin (WGA) wer e isolated via flow cytometry. These results support growing evidence that fetal, and perhaps embryonic, hematopoietic tissues may be excellent altern ative sources of highly proliferative hematopoietic cells as targets for so matic gene therapy.