Intraembryonic, but not yolk sac hematopoietic precursors, isolated before circulation, provide long-term multilineage reconstitution.
The relative contribution of yolk sac and intraembryonic precursors to hematopoiesis has been a matter of long-standing controversy. As reconstitution activity has so far only been found in embryonic tissues after the onset of circulation, the origin of reconstituting cells could not be formally established. Here, we separated yolk sac and intraembryonic splanchnopleura prior to circulation and maintained the explants in organ culture before transfer. Precursors derived from the intraembryonic site generated multilineage hematopoietic progeny in adult mice for more than 6 months. Yolk sac cells only provided myeloid short-term reconstitution. The results reveal a differential hematopoietic capacity of precirculation embryonic tissues in vivo, and indicate that the only cells capable of adult long-term hematopoiesis are of intraembryonic origin.
Cumano
A
A
Unité du Développement des Lymphocytes (URA CNRS 1961), Institut Pasteur, Rue du Dr. Roux, 75724 Paris, France.
Ferraz
J C
JC
Klaine
M
M
Di Santo
J P
JP
Godin
I
I
D000818:Animals; D002454:Cell Differentiation; D019070:Cell Lineage; D004268:DNA-Binding Proteins; D004622:Embryo, Mammalian / Q000166:cytology*; D005260:Female; D006412:Hematopoietic Stem Cells / Q000502:physiology*; D015395:Histocompatibility Antigens Class I / Q000032:analysis; D051379:Mice; D008810:Mice, Inbred C57BL; D009924:Organ Culture Techniques; D011247:Pregnancy; D015017:Yolk Sac / Q000166:cytology*
D004268:DNA-Binding Proteins; D015395:Histocompatibility Antigens Class I; C499308:Rag2 protein, mouse; C064655:V(D)J recombination activating protein 2