Takizawa, Hitoshi Regoes, Roland R. Boddupalli, Chandra S. Bonhoeffer, Sebastian Manz, Markus G. 2011-02-07 Hematopoietic stem cells (HSCs) maintain blood production. How often mouse HSCs divide and whether each HSC contributes simultaneously, sequentially, or repetitively to hematopoiesis remains to be determined. We track division of 5-(and-6)-carboxyfluorescein diacetate succinimidyl ester (CFSE)–labeled HSC in vivo. We found that, in steady-state mice, bone marrow cells capable of reconstituting lifelong hematopoiesis are found within both fast-cycling (undergoing five or more divisions in 7 wk) and quiescent (undergoing zero divisions in 12–14 wk) lineage marker–negative c-Kit+ Sca-1+ populations. The contribution of each population to hematopoiesis can fluctuate with time, and cells with extensive proliferative history are prone to return to quiescence. Furthermore, injection of the bacterial component lipopolysaccharide increased the proliferation and self-renewal capacity of HSCs. These findings suggest a model in which all HSCs undergo dynamic and demand- adapted entry into and exit out of the cell cycle over time. This may facilitate a similar degree of turnover of the entire HSC pool at the end of life. application/pdf https://n2t.net/ark:/12658/srd1319016 https://susi.usi.ch/global/documents/319016 https://susi.usi.ch/documents/319016/files/Takizawa_JEM_2011.pdf eng info:eu-repo/semantics/altIdentifier/doi/10.1084/jem.20101643 info:eu-repo/semantics/altIdentifier/ark/12658/srd1319016 info:eu-repo/semantics/openAccess CC BY-NC-SA Journal of experimental medicine. - 2011, vol. 208, no. 2, p. 273-284 info:eu-repo/classification/udc/61 Dynamic variation in cycling of hematopoietic stem cells in steady state and inflammation http://purl.org/coar/resource_type/c_6501