title: Runx1 expression marks long-term repopulating hematopoietic stem cells in the midgestation mouse embryo.
abstract: Hematopoietic stem cells (HSCs) are first found in the aorta-gonad-mesonephros region and vitelline and umbilical arteries of the midgestation mouse embryo. Runx1 (AML1), the DNA binding subunit of a core binding factor, is required for the emergence and/or subsequent function of HSCs. We show that all HSCs in the embryo express Runx1. Furthermore, HSCs in Runx1(+/-) embryos are heterogeneous and include CD45(+) cells, endothelial cells, and mesenchymal cells. Comparison with wild-type embryos showed that the distribution of HSCs among these various cell populations is sensitive to Runx1 dosage. These data provide the first morphological description of embryonic HSCs and contribute new insight into their cellular origin.
authors.affiliation: Department of Biochemistry, Dartmouth Medical School, Hanover, NH 03755, USA.
authors.forename: Trista E
authors.initials: TE
authors.lastname: North
authors.forename: Marella F T R
authors.initials: MF
authors.lastname: de Bruijn
authors.forename: Terryl
authors.initials: T
authors.lastname: Stacy
authors.forename: Laleh
authors.initials: L
authors.lastname: Talebian
authors.forename: Evan
authors.initials: E
authors.lastname: Lind
authors.forename: Catherine
authors.initials: C
authors.lastname: Robin
authors.forename: Michael
authors.initials: M
authors.lastname: Binder
authors.forename: Elaine
authors.initials: E
authors.lastname: Dzierzak
authors.forename: Nancy A
authors.initials: NA
authors.lastname: Speck
mesh_terms: D000818:Animals; D015415:Biomarkers / Q000032:analysis; D019070:Cell Lineage; D050676:Core Binding Factor Alpha 2 Subunit; D004268:DNA-Binding Proteins / Q000032:analysis* / Q000235:genetics / Q000378:metabolism*; D004622:Embryo, Mammalian / Q000166:cytology*; D004730:Endothelium, Vascular / Q000737:chemistry / Q000196:embryology; D018628:Gene Dosage; D005865:Gestational Age; D006412:Hematopoietic Stem Cells / Q000737:chemistry* / Q000145:classification; D016130:Immunophenotyping; D017493:Leukocyte Common Antigens / Q000737:chemistry; D008648:Mesoderm / Q000737:chemistry; D051379:Mice; D008810:Mice, Inbred C57BL; D008954:Models, Biological; D011518:Proto-Oncogene Proteins; D014157:Transcription Factors / Q000032:analysis* / Q000235:genetics / Q000378:metabolism*
chemical_list: D015415:Biomarkers; D050676:Core Binding Factor Alpha 2 Subunit; D004268:DNA-Binding Proteins; D011518:Proto-Oncogene Proteins; C493726:Runx1 protein, mouse; D014157:Transcription Factors; D017493:Leukocyte Common Antigens