title: Expression of AA4.1 marks lymphohematopoietic progenitors in early mouse development.
abstract: The hematopoietic system of mice is established during the early to midgestational stage of development. However, the earliest lymphohematopoietic progenitors that appear during mouse development have been less well characterized compared with the hematopoietic stem cell compartment of fetal liver and bone marrow. We isolated the earliest lymphohematopoietic progenitors by using embryonic stem (ES) cell culture in vitro. Cells with the c-Kit(+)Lin(-) cell surface phenotype were present abundantly in ES cells cocultured with stromal cell lines. We further separated the cells into two distinct cell subsets based on AA4.1 expression. Although AA4.1(+) and AA4.1(-) cells had equivalent potency to generate myeloid cell lineages, the lymphoid potential in ES-cell-derived cells was largely restricted to the cells expressing AA4.1. The same cell type was present abundantly in the early yolk sac and in fewer numbers (approximately 5% of that in the yolk sac) in the caudal half of the developing embryos. These data suggest that AA4.1 is a cell surface marker that can identify the earliest lymphohematopoietic progenitors in mouse development.
authors.affiliation: Department of Pathology, Institute of Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, CA 94305, USA. yamanet@doc.medic.mie-u.ac.jp
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Yamane
authors.forename: Naoki
authors.initials: N
authors.lastname: Hosen
authors.forename: Hidetoshi
authors.initials: H
authors.lastname: Yamazaki
authors.forename: Irving L
authors.initials: IL
authors.lastname: Weissman
mesh_terms: D000818:Animals; D015415:Biomarkers / Q000378:metabolism; D019070:Cell Lineage; D002469:Cell Separation; D047108:Embryonic Development; D053595:Embryonic Stem Cells / Q000378:metabolism; D005260:Female; D018380:Hematopoietic Stem Cell Transplantation; D006412:Hematopoietic Stem Cells / Q000378:metabolism*; D008297:Male; D008562:Membrane Glycoproteins / Q000096:biosynthesis*; D051379:Mice; D008810:Mice, Inbred C57BL; D023461:Myeloid Progenitor Cells / Q000378:metabolism*; D019009:Proto-Oncogene Proteins c-kit / Q000378:metabolism; D011951:Receptors, Complement / Q000096:biosynthesis*
chemical_list: D015415:Biomarkers; D008562:Membrane Glycoproteins; D011951:Receptors, Complement; C032402:complement 1q receptor; D019009:Proto-Oncogene Proteins c-kit