Gene expression profiles in murine hematopoietic stem cells revisited: analysis of cDNA libraries reveals high levels of translational and metabolic activities

¹ University Hospital of Essen, The Clinic of Hematology, Essen, Germany
² University Hospital of Essen, The Institute of Cell Biology, Essen, Germany
³ University Hospital of Essen, Institute for Medical Informatics, Biometry and Epidemiology, Essen, Germany
⁴ Leukaemia Foundation of Queensland Laboratory, Queensland Institute of Medical Research, Brisbane, Australia
⁵ Institute of Cellular and Organismic Biology / Genomics Research Center, Academia Sinica, Taipei, Taiwan

^* To whom correspondence should be addressed. E-mail: andreas.huettmann{at}uni-essen.de.

	Abstract

Gene expression studies from hematopoietic stem cell (HSC) populations purified to variable degrees have defined a set of stemness genes. Unexpectedly, results also hinted towards a HSC chromatin poised in a wide-open state. In order to provide a robust tool for further studies into the molecular biology of HSCs, the studies herein describe the construction and comparative molecular analysis of -phage cDNA libraries from highly purified HSCs which retained their long term repopulating activities (long term hematopoietic stem cells; LT-HSCs), and from short term repopulating HSCs (ST-HSCs) which were largely depleted of these activities. Microarray analysis of the libraries confirmed the previous results but also revealed an unforseen preferential expression of translation and metabolism associated genes in the LT-HSCs. Therefore these data indicate that HSCs are quiescent only in regard of proliferative activities, but are in a state of readiness to provide the metabolic and translational activities required following induction of proliferation and exit from the HSC pool.