title: Differential expression of KDR/VEGFR-2 and CD34 during mesoderm development of the early human embryo.
abstract: Recent findings on vertebrate embryos have provided compelling evidence for the existence of hemangioblasts, i.e. common precursors for endothelial and hematopoietic cells, characterized by expression of the VEGFR2/Flk1 receptor. We describe here a population of KDR+ CD34- mesoderm cells that emerges in early-somitic human embryos, by the beginning of the 4th week of gestation. In the developing blood vessels, KDR-expressing CD34- cells gradually coexpress increasing levels of CD34 antigen. Remarkably, as development proceeds, a KDR+ CD34- contingent persists in the paraaortic splanchnopleura until just prior to the emergence of aorta-associated hematopoietic cell clusters. These observations suggest that KDR+ CD34- mesodermal cells might represent the putative hemangioblastic precursor of human hematopoietic and endothelial lineages.
authors.affiliation: Institut d'Embryologie Cellulaire et Moléculaire, CNRS UPR 9064, 49bis, avenue de la Belle Gabrielle, 94736, Nogent-sur-Marne Cedex, France.
authors.forename: F
authors.initials: F
authors.lastname: Cortés
authors.forename: C
authors.initials: C
authors.lastname: Debacker
authors.forename: B
authors.initials: B
authors.lastname: Péault
authors.forename: M C
authors.initials: MC
authors.lastname: Labastie
mesh_terms: D018952:Antigens, CD34 / Q000032:analysis / Q000378:metabolism*; D004622:Embryo, Mammalian / Q000033:anatomy & histology* / Q000378:metabolism*; D006801:Humans; D008648:Mesoderm / Q000378:metabolism*; D020794:Receptor Protein-Tyrosine Kinases / Q000032:analysis / Q000378:metabolism*; D017978:Receptors, Growth Factor / Q000032:analysis / Q000378:metabolism*; D040262:Receptors, Vascular Endothelial Growth Factor; D013997:Time Factors
chemical_list: D018952:Antigens, CD34; D017978:Receptors, Growth Factor; D020794:Receptor Protein-Tyrosine Kinases; D040262:Receptors, Vascular Endothelial Growth Factor