New evidence supporting megakaryocyte-erythrocyte potential of flk2/flt3+ multipotent hematopoietic progenitors.
A model of hematopoietic development wherein multipotentiality is conserved until segregation of myeloid and lymphoid potential has recently been challenged, proposing that megakaryocyte/erythrocyte (MegE) potential is lost in Flk2/Flt3-expressing early progenitors. Here, we used sensitive in vivo approaches to quantitatively and kinetically assess the MegE potential of hematopoietic stem cells and various Flk2(+) early progenitors and compared it with the MegE potential of downstream committed myeloid and lymphoid progenitors and with their ability to give rise to mature myelomonocytic and lymphoid cells. We demonstrate that Flk2(+) early progenitors retain MegE potential in vivo both at the population and clonal levels. These results indicate that Flk2 expression by early progenitors is not at the expense of full multipotency and support the current model of hematopoietic development with segregation of myeloid and lymphoid lineages from multipotent progenitors.
Forsberg
E Camilla
EC
Institute of Stem Cell Biology and Regenerative Medicine, Departments of Pathology and Developmental Biology, Stanford University School of Medicine, Stanford, CA 94305, USA. cforsber@stanford.edu
Serwold
Thomas
T
Kogan
Scott
S
Weissman
Irving L
IL
Passegué
Emmanuelle
E
D000818:Animals; D002452:Cell Count; D018929:Cell Culture Techniques; D002454:Cell Differentiation; D019070:Cell Lineage; D002478:Cells, Cultured; D004912:Erythrocytes / Q000502:physiology*; D005434:Flow Cytometry; D015870:Gene Expression / Q000235:genetics / Q000502:physiology; D006412:Hematopoietic Stem Cells / Q000166:cytology / Q000502:physiology*; D007700:Kinetics; D008533:Megakaryocytes / Q000502:physiology*; D051379:Mice; D020297:Mice, Congenic; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D008954:Models, Biological; D014184:Transplantation, Homologous; D014965:X-Rays; D051941:fms-Like Tyrosine Kinase 3 / Q000502:physiology*
D051941:fms-Like Tyrosine Kinase 3