title: Expression of notch receptors, notch ligands, and fringe genes in hematopoiesis.
abstract: OBJECTIVE
  Hematopoiesis is the process by which mature blood cell types are generated from a small population of pluripotent hematopoietic stem cells. How these cells undergo fate selection, however, is not fully understood. The Notch signaling system is known to mediate cell fate decisions of multipotent precursors in a wide range of complex animals throughout development. As Notch signaling involves cell-cell interactions, we sought to determine the expression of Notch receptors, ligands, and regulators in individual cell populations along the hematopoietic differentiation pathway.
  
  
  METHODS
  Described here is a single cell RT-PCR analysis of Notch1, Notch3, Notch4, Notch ligands (Dll1 and Jagged1), and Fringe gene expression in cells of the blood system. As previously described, single cell globally amplified cDNA was generated by RT-PCR from various hematopoietic precursor cells whose potential was known from sibling analysis. A precursor hierarchy slot blot was created containing these cDNAs as well as samples from maturing blood cell populations and two fibroblast cell lines. The precursor slot blot was screened with probes for each of the candidate genes.
  
  
  RESULTS
  Macrophage precursors expressed high levels of Notch1 transcript, while maturing macrophages expressed high levels of both Notch1 and Notch4. The Jagged 1 ligand transcript was highly expressed in terminally maturing cells including mast cells and megakaryocytes. In contrast, the Manic Fringe gene was highly expressed in uncommitted bi- and tri-potential precursors as well as in committed neutrophil and macrophage precursors.
  
  
  CONCLUSIONS
  Distinct expression patterns of Jagged1 and Manic Fringe suggest that their corresponding proteins could regulate cell fate choices during hematopoiesis and may be responsible for regulating communication between lineage compartments during hematopoietic development.
authors.affiliation: Program in Cancer & Blood Research and, Toronto, Ontario, Canada.
authors.forename: N
authors.initials: N
authors.lastname: Singh
authors.forename: R A
authors.initials: RA
authors.lastname: Phillips
authors.forename: N N
authors.initials: NN
authors.lastname: Iscove
authors.forename: S E
authors.initials: SE
authors.lastname: Egan
mesh_terms: D000818:Animals; D001854:Bone Marrow Cells / Q000166:cytology / Q000378:metabolism*; D002135:Calcium-Binding Proteins; D029721:Drosophila Proteins; D005786:Gene Expression Regulation; D006410:Hematopoiesis / Q000235:genetics*; D006412:Hematopoietic Stem Cells / Q000166:cytology / Q000378:metabolism; D019476:Insect Proteins / Q000235:genetics*; D036341:Intercellular Signaling Peptides and Proteins; D047908:Intracellular Signaling Peptides and Proteins; D000072100:Jagged-1 Protein; D008565:Membrane Proteins / Q000235:genetics*; D051379:Mice; D008807:Mice, Inbred BALB C; D017351:N-Acetylglucosaminyltransferases; D011506:Proteins / Q000235:genetics*; D011518:Proto-Oncogene Proteins / Q000235:genetics*; D051881:Receptor, Notch1; D000071656:Receptor, Notch3; D000074562:Receptor, Notch4; D011956:Receptors, Cell Surface / Q000235:genetics; D051880:Receptors, Notch; D020133:Reverse Transcriptase Polymerase Chain Reaction; D000072099:Serrate-Jagged Proteins; D014157:Transcription Factors; D014158:Transcription, Genetic
chemical_list: D002135:Calcium-Binding Proteins; D029721:Drosophila Proteins; D019476:Insect Proteins; D036341:Intercellular Signaling Peptides and Proteins; D047908:Intracellular Signaling Peptides and Proteins; C000606273:JAG1 protein, human; C000606274:Jag1 protein, mouse; D000072100:Jagged-1 Protein; D008565:Membrane Proteins; C106075:NOTCH4 protein, human; C497762:Notch1 protein, mouse; C499373:Notch3 protein, mouse; D011506:Proteins; D011518:Proto-Oncogene Proteins; D051881:Receptor, Notch1; D000071656:Receptor, Notch3; D000074562:Receptor, Notch4; D011956:Receptors, Cell Surface; D051880:Receptors, Notch; C000606278:Ser protein, Drosophila; D000072099:Serrate-Jagged Proteins; D014157:Transcription Factors; C064045:delta protein; C073572:Notch4 protein, mouse; D017351:N-Acetylglucosaminyltransferases; C090576:fng protein, Drosophila