RT Journal Article ID 53b592135dac5423 A1 Morales-Alcelay, S. A1 Copin, S. G. A1 Martinez, J. A. A1 Morales, P. A1 Minguet, S. A1 Gaspar, M. L. A1 Marcos, M. A. R. T1 Developmental Hematopoiesis JF Critical Reviews™ in Immunology JO CRI YR 1998 FD 1998-12-20 VO 18 IS 6 SP 485 OP 501 K1 embryonic lymphohemopoiesis K1 hematopoietic stem cells K1 angiogenesis K1 gene targeting K1 gene therapy. AB Hematopoiesis is a developmental process that evolves throughout the lifespan of an individual. Most work in the field has focused on events occurring in the adult bone marrow (BM). In the embryo, blood and endothelial cell generation begins very early after gastrulation, in defined intraembryonic mesodermic sites. Recent multidisciplinary studies, taking advantage of classic embryological and gene targeting technology in various species, have provided a new image of embryofetal lymphohemopoiesis, which includes the suggestion of developmental compartmentalization or waves. The first hematopoietic stem cells (HSC) migrate further and home in an ordered sequence of supporting microenvironments depending on scarcely known molecular requirements. These early hematopoietic progenitors show important differences in their cell biology and differentiation potentialities with respect to those present in adult stages; this fact, together with specific microenvironmental influences, define a process that diverges significantly from that occurring in the BM. Here, we update the latest developments in the field, the new understanding of lymphohemopoiesis in prenatal life, and the novel questions that this emerging paradigm is producing. PB Begell House LK https://www.dl.begellhouse.com/journals/2ff21abf44b19838,390d3fc461d10f95,53b592135dac5423.html