All B cells are progeny of endothelial cells: a new perspective

We present here a speculative view of embryonic hematopoiesis. We do this w ith the hope of finding directions for Future study, keeping in mind that o ur model may diverge from the real situation. However, we want to emphasize that previous models have neglected the possibility that endothelial cells (EC) represent a progenitor of hematopoietic cells (HPC). Emerging evidenc e, including our own, and previous histological studies argue for the prese nce of hemogenic EC. We discuss seemingly contradictory points of view of e mbryonic hematopoiesis, such as the origin of lymphogenic progenitors, and have shown that they may be resolved more satisfactorily by introducing thi s notion. Obviously, a good model should be a testable one, so we are curre ntly developing experimental systems to demonstrate that all B cells are, i ndeed, the progeny of EC.