title: Genetically determined variation in the number of phenotypically defined hematopoietic progenitor and stem cells and in their response to early-acting cytokines.
abstract: Quantitative trait analysis may shed light on mechanisms regulating hematopoiesis in vivo. Strain-dependent variation existed among C57BL/6 (B6), DBA/2, and BXD recombinant inbred mice in the responsiveness of primitive progenitor cells to the early-acting cytokines kit ligand, flt3 ligand, and thrombopoietin. A significant quantitative trait locus was found on chromosome 2 that could not be confirmed in congenic mice, however, probably because of epistasis. Because it has been shown that alleles of unknown X-linked genes confer a selective advantage to hematopoietic stem cells in vivo in humans and in cats, we also analyzed reciprocal male D2B6F1 and B6D2F1 mice, revealing an X-linked locus regulating the responsiveness of progenitor and stem cells to early-acting factors. Among DBA/2, B6, and BXD recombinant inbred mice, correlating genetic variation was found in the absolute number and frequency of Lin(-)Sca1(++)kit(+) cells, which are highly enriched in hematopoietic progenitor and stem cells, and in the number of Lin(-)Sca1(++)kit(-) cells, a population whose biologic significance is unknown, suggesting that both populations are functionally related. Suggestive quantitative trait loci (QTLs) for the number of Lin(-)Sca1(++) cells on chromosomes 2, 4, and 7 were confirmed in successive rounds of mapping. The locus on chromosome 2 was confirmed in congenic mice. We thus demonstrated genetic variation in the response to cytokines critical for hematopoiesis in vivo and in the pool size of cells belonging to a phenotype used to isolate essentially pure primitive progenitor and stem cells, and we identified loci that may be relevant to the regulation of hematopoiesis in steady state.
authors: Carl C. Icahn Institute for Gene Therapy and Molecular Medicine, Mount Sinai School of Medicine, New York, NY 10029, USA.
authors: Els
authors: E
authors: Henckaerts
authors: Hartmut
authors: H
authors: Geiger
authors: Jessica C
authors: JC
authors: Langer
authors: Patricia
authors: P
authors: Rebollo
authors: Gary
authors: G
authors: Van Zant
authors: Hans-Willem
authors: HW
authors: Snoeck
mesh_terms: D000818:Animals; D002455:Cell Division / Q000187:drug effects; D003114:Colony-Forming Units Assay; D003433:Crosses, Genetic; D016207:Cytokines / Q000494:pharmacology*; D005260:Female; D014644:Genetic Variation; D006410:Hematopoiesis; D006412:Hematopoietic Stem Cells / Q000166:cytology / Q000187:drug effects / Q000502:physiology*; D008297:Male; D008565:Membrane Proteins / Q000494:pharmacology; D051379:Mice; D008810:Mice, Inbred C57BL; D008811:Mice, Inbred DBA; D010641:Phenotype; D011994:Recombinant Proteins / Q000494:pharmacology; D013045:Species Specificity; D019089:Stem Cell Factor / Q000494:pharmacology; D013926:Thrombopoietin / Q000494:pharmacology
chemical_list: D016207:Cytokines; D008565:Membrane Proteins; D011994:Recombinant Proteins; D019089:Stem Cell Factor; C084881:flt3 ligand protein; D013926:Thrombopoietin