title: Intra-embryonic haemopoietic cells and early MHC expression.
abstract: In the avian embryo the haemopoietic stem cells originate from the intra-embryonic area near dorsal aorta. The surface-marker expression of haemopoietic stem cells and their potential to produce different haemopoietic cells are still largely unknown. The surface antigen expression and particularly the MHC antigen expression on intra-embryonic haemopoietic cells was studied. Expression of B-F antigens, homologous to mammalian MHC class-I antigens, was found already on embryonic day (ED) 5. The first B-L antigens, analogous to mammalian MHC class-II antigens, were detected also from ED5 onwards. The appearance of surface antigens defined by MoAbs T10A6 and 3-298 during embryogenesis also was studied. The antigen defined with T10A6 was detected from ED4 onwards on endothelial cells but not on haemopoietic cells in the para-aortic region. The first 3-298+ haemopoietic cells were found on ED6, whereas endothelial cells were negative. These findings imply that some surface markers are shared with haemopoietic and endothelial cells indicating either a common embryonic origin or the importance of these molecules in embryonic stem-cell homing.
authors.affiliation: Department of Medical Microbiology, Turku University, Finland.
authors.forename: M
authors.initials: M
authors.lastname: Lampisuo
authors.forename: O
authors.initials: O
authors.lastname: Lassila
mesh_terms: D000818:Animals; D000954:Antigens, Surface / Q000032:analysis; D002642:Chick Embryo; D005314:Embryonic and Fetal Development; D005434:Flow Cytometry; D006412:Hematopoietic Stem Cells / Q000737:chemistry / Q000276:immunology*; D000949:Histocompatibility Antigens Class II / Q000032:analysis; D007150:Immunohistochemistry; D008285:Major Histocompatibility Complex / Q000502:physiology*; D008562:Membrane Glycoproteins / Q000032:analysis; D001613:beta 2-Microglobulin / Q000032:analysis
chemical_list: D000954:Antigens, Surface; D000949:Histocompatibility Antigens Class II; C041136:Ia-like antigens, avian; D008562:Membrane Glycoproteins; D001613:beta 2-Microglobulin