title: Green fluorescent protein transgene driven by Kit regulatory sequences is expressed in hematopoietic stem cells.
abstract: BACKGROUND
  The transcriptional regulation of stem cell genes is still poorly understood. Kit, encoding the stem cell factor receptor, is a pivotal molecule for multiple types of stem/progenitor cells. We previously generated mouse lines expressing transgenic green fluorescent protein under the control of Kit promoter/first intron regulatory elements, and we demonstrated expression in hematopoietic progenitors.
  
  
  METHODS
  In the present work we investigated whether the transgene is also expressed in hematopoietic stem cells of adult bone marrow and fetal liver. To this purpose, we tested, in long-term repopulating assays, cell fractions expressing different levels of green fluorescent protein within Kit-positive or SLAM-selected populations.
  
  
  RESULTS
  The experiments demonstrated transgene expression in both fetal and adult hematopoietic stem cells and indicated that the transgene is transcribed at distinctly lower levels in hematopoietic stem cells than in pluripotent and committed progenitors.
  
  
  CONCLUSIONS
  These results, together with previous data, show that a limited subset of DNA sequences drives gene expression in number of stem cell types (hematopoietic stem cells, primordial germ cells, cardiac stem cells). Additionally, our results might help to further improve high level purification of hematopoietic stem cells for experimental purposes. Finally, as the Kit/green fluorescent protein transgene is expressed in multiple stem cell types, our transgenic model provides powerful in vivo system to track these cells during development and tissue regeneration.
authors.affiliation: Institute of Biomedical Technologies, National Council of Research, Pisa, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Cerisoli
authors.forename: Letizia
authors.initials: L
authors.lastname: Cassinelli
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Lamorte
authors.forename: Stefania
authors.initials: S
authors.lastname: Citterio
authors.forename: Francesca
authors.initials: F
authors.lastname: Bertolotti
authors.forename: Maria Cristina
authors.initials: MC
authors.lastname: Magli
authors.forename: Sergio
authors.initials: S
authors.lastname: Ottolenghi
mesh_terms: D000818:Animals; D001853:Bone Marrow / Q000378:metabolism; D016026:Bone Marrow Transplantation; D002469:Cell Separation; D003114:Colony-Forming Units Assay; D005260:Female; D005434:Flow Cytometry / Q000379:methods; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism*; D006412:Hematopoietic Stem Cells / Q000166:cytology / Q000378:metabolism*; D008099:Liver / Q000196:embryology / Q000378:metabolism; D008297:Male; D051379:Mice; D008822:Mice, Transgenic; D019009:Proto-Oncogene Proteins c-kit / Q000235:genetics*; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D012045:Regulatory Sequences, Nucleic Acid / Q000235:genetics*
chemical_list: D011993:Recombinant Fusion Proteins; D049452:Green Fluorescent Proteins; D019009:Proto-Oncogene Proteins c-kit