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 Printable version |
Ontogeny of hemopoietic stem cells : animal models |
Hématologie. Volume 1, Number 4, 295-302, Juillet - Août 1995, REVUES ET MINI-REVUES
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 Résumé
Article gratuit
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Author(s) : Françoise Dieterlen-Lièvre |
Summary : During ontogeny, extrinsic hemopoietic stem cells (HSC) colonize the stromal rudiments of blood forming organs. The only organ which produces its own HSC is the yolk sac. This appendage has therefore been considered as the unique site where these cells appear [1]. Using an avian model in which the embryo is associated to a foreign yolk sac (quail embryo on chick yolk sac, or chick embryo on chick yolk sac with differing lg allotypes or MHC haplotypes), we have demonstrated that HSC of intraembryonic origin relay yolk sac HSC and are the only ones that seed the definitive organ rudiments. In birds the origin of intraembryonic HSC could be circumscribed to the region of the aorta. We recently brought about evidence for a similar evolution in mouse ; amplification and differentiation of hemopoietic cells in an appropriate two phase-culture system made it possible to detect the emergence of a secondary wave of HSC emerging simultaneously in a region of the embryo called the " paraaortic splanchnopleura " and in the yolk sac. These HSC appear twenty-four hours after the primary yolk sac HSC, they are absent from the remainder of the embryo, after yolk sac and P-Sp have been dissected away. |
Keywords : hematopoietic stem cells, embryo, birds, mammals. |
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