title: Combinatorial Gata2 and Sca1 expression defines hematopoietic stem cells in the bone marrow niche.
abstract: The interaction between stem cells and their supportive microenvironment is critical for their maintenance, function, and survival. Whereas hematopoietic stem cells (HSCs) are among the best characterized of tissue stem cells, their precise site of residence (referred to as the niche) in the adult bone marrow has not been precisely defined. In this study, we found that a Gata2 promoter directs activity in all HSCs. We show that HSCs can be isolated efficiently from bone marrow cells by following Gata2-directed GFP fluorescence, and that they can also be monitored in vivo. Each individual GFP-positive cell lay in a G0/G1 cell cycle state, in intimate contact with osteoblasts beside the endosteum, at the edge of the bone marrow. We conclude that the HSC niche is composed of solitary cells and that adult bone marrow HSC are not clustered.
authors.affiliation: Japan Science and Technology Agency (JST)-Exploratory Research for Advanced Technology (ERATO) Environmental Response Project, Center for Tsukuba Advanced Research Alliance, University of Tsukuba, 1-1-1 Tennoudai, Tsukuba 305-8577, Japan.
authors.forename: Norio
authors.initials: N
authors.lastname: Suzuki
authors.forename: Osamu
authors.initials: O
authors.lastname: Ohneda
authors.forename: Naoko
authors.initials: N
authors.lastname: Minegishi
authors.forename: Mitsuo
authors.initials: M
authors.lastname: Nishikawa
authors.forename: Takayuki
authors.initials: T
authors.lastname: Ohta
authors.forename: Satoru
authors.initials: S
authors.lastname: Takahashi
authors.forename: James Douglas
authors.initials: JD
authors.lastname: Engel
authors.forename: Masayuki
authors.initials: M
authors.lastname: Yamamoto
mesh_terms: D000818:Animals; D000067696:Ataxin-1; D000067528:Ataxins; D001854:Bone Marrow Cells / Q000166:cytology* / Q000502:physiology; D002453:Cell Cycle / Q000235:genetics; D002454:Cell Differentiation / Q000235:genetics; D050989:GATA2 Transcription Factor / Q000235:genetics* / Q000378:metabolism*; D017930:Genes, Reporter; D049452:Green Fluorescent Proteins / Q000032:analysis / Q000235:genetics; D006412:Hematopoietic Stem Cells / Q000737:chemistry / Q000166:cytology* / Q000378:metabolism; D051379:Mice; D008817:Mice, Mutant Strains; D009419:Nerve Tissue Proteins / Q000235:genetics / Q000378:metabolism*; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism*; D010006:Osteoblasts / Q000166:cytology / Q000378:metabolism; D011401:Promoter Regions, Genetic
chemical_list: D000067696:Ataxin-1; D000067528:Ataxins; C000593750:Atxn1 protein, mouse; D050989:GATA2 Transcription Factor; C494712:Gata2 protein, mouse; D009419:Nerve Tissue Proteins; D009687:Nuclear Proteins; D049452:Green Fluorescent Proteins