ArrayExpress Uploader0mousesorted HSCs (lin-Mac-1 low sca1+ckit+CD150+CD48-)not specifiedfetalsorted HSCs (lin-Mac-1 low sca1+ckit+CD150+CD48-)not specifiedfetalsorted HSCs (lin-Mac-1 low sca1+ckit+CD150+CD48-)not specifiedfetalsorted HSCs (lin-sca1+ckit+CD150+CD48-)wild typeadultsorted HSCs (lin-sca1+ckit+CD150+CD48-)wild typeadultsorted HSCs (lin-sca1+ckit+CD150+CD48-)wild typeadultsorted HSCs (lin-sca1+ckit+CD150+CD48-)Pu.1 knock-in (PU.1ki/ki)adultsorted HSCs (lin-sca1+ckit+CD150+CD48-)Pu.1 knock-in (PU.1ki/ki)adultsorted HSCs (lin-sca1+ckit+CD150+CD48-)Pu.1 knock-in (PU.1ki/ki)adultsorted HSCs (lin-sca1+ckit+CD150+CD48-)wild typeadultsorted HSCs (lin-sca1+ckit+CD150+CD48-)wild typeadultsorted HSCs (lin-sca1+ckit+CD150+CD48-)wild typeadultsorted HSCs (lin-sca1+ckit+CD150+CD48-)wild typeadultsorted HSCs (lin-sca1+ckit+CD150+CD48-)Pu.1 knock-in (PU.1ki/ki)adultsorted HSCs (lin-sca1+ckit+CD150+CD48-)Pu.1 knock-in (PU.1ki/ki)adultsorted HSCs (lin-sca1+ckit+CD150+CD48-)Pu.1 knock-in (PU.1ki/ki)adultsorted HSCs (lin-sca1+ckit+CD150+CD48-)Pu.1 knock-in (PU.1ki/ki)adult7078arrayexpress_sid6In blood, the transcription factor C/EBPa is essential for myeloid differentiation and has been implicated in regulating self-renewal of...E-GEOD-42234/profile/8773/arrayexpressuploader317cellliverDec.12, 2014Falsecebpa-controls-acquisition-and-maintenance-of-adulE-GEOD-42234_A-AFFY-45C/EBPa controls acquisition and maintenance of adult hematopoietic stem cell quiescenceNov.12, 2014In blood, the transcription factor C/EBPa is essential for myeloid differentiation and has been implicated in regulating self-renewal of fetal liver hematopoietic stem cells (HSCs). However, its function in adult HSCs is unknown. Here, using an inducible knockout model, we found that C/EBPa deficient adult HSCs underwent a pronounced expansion with enhanced proliferation, characteristics resembling fetal liver HSCs. Consistently, transcription profiling of C/EBPa deficient HSCs revealed a gene expression program similar to fetal liver HSCs. Moreover we observed that age-specific C/EBPa expression correlated with its inhibitory effect on the HSC cell cycle. Mechanistically, we identified N-Myc as a C/EBPa downstream target. C/EBPa upregulation during HSC transition from an active fetal state to a quiescent adult state was accompanied by down-regulation of N-Myc, and loss of C/EBPa resulted in de-repression of NMyc. Our data establish that C/EBPa acts as a molecular switch between fetal and adult states of HSC in part via transcriptional repression of the proto-oncogene N-Myc. HSCs of Pu.1 knock-in (PU.1ki/ki) mice were used for RNA extraction and hybridization on Affymetrix microarrays. We compared these microarray samples with the corresponding wild type.http://www.ebi.ac.uk/arrayexpress/experiments/E-GEOD-42234http://www.ebi.ac.uk/arrayexpress/experiments/E-GEOD-42234/samples/