Spatial differences in hematopoiesis but not in stem cells indicate a lack of regional patterning in definitive hematopoietic stem cells.
Most tissues are patterned so that progenitors in different locations are programmed to have different properties. Stem cells from different regions of the nervous system acquire intrinsic differences in their properties as they migrate through distinct environments. Hematopoietic stem cells (HSCs) also migrate through diverse environments throughout life, raising the question of whether HSCs also acquire at least transient changes in their properties as they are exposed to diverse environments. Although we observed significant differences in hematopoiesis between the fetal liver and fetal spleen, we were not able to detect phenotypic, functional, or gene expression differences between the HSCs in these organs. Regional differences in definitive hematopoiesis are therefore not determined by regional differences between HSCs. We were also not able to detect phenotypic, functional, or gene expression differences between HSCs in different adult bone marrow compartments. Our failure to detect differences among stem cells from different regions of the hematopoietic system at the same time during development suggests that the hematopoietic system has evolved mechanisms to prevent the spatial reprogramming of HSC properties as they migrate between distinct environments.
Kiel
Mark J
MJ
Howard Hughes Medical Institute, University of Michigan, Ann Arbor, MI 48109-0934, USA.
Iwashita
Toshihide
T
Yilmaz
Omer H
OH
Morrison
Sean J
SJ
D000818:Animals; D019521:Body Patterning; D002478:Cells, Cultured; D003114:Colony-Forming Units Assay; D047108:Embryonic Development; D005260:Female; D005333:Fetus / Q000502:physiology; D020869:Gene Expression Profiling; D018507:Gene Expression Regulation, Developmental; D006410:Hematopoiesis / Q000502:physiology*; D017493:Leukocyte Common Antigens / Q000235:genetics; D008099:Liver / Q000196:embryology; D051379:Mice; D008810:Mice, Inbred C57BL; D011247:Pregnancy; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013154:Spleen / Q000196:embryology; D013234:Stem Cells / Q000166:cytology / Q000502:physiology*
D017493:Leukocyte Common Antigens