Expression data from side population subfraction hematopoietic stem cells

The traditional view of hematopoiesis has been that all the cells of the peripheral blood are the progeny of a unitary homogeneous pool of hematopoietic stem cells (HSCs). Recent evidence suggests that the hematopoietic system is actually maintained by a consortium of HSC subtypes with distinct functional characteristics. We show here that myeloid-biased HSCs (My-HSCs) and lymphoid-biased (Ly-HSCs) can be purified according to their capacity for Hoechst dye efflux in combination with canonical HSC markers. We used microarray expression profiling to determine the transcriptional profiles of myeloid-biased lower-SP HSCs and lymphoid-biased upper-SP HSCs Three biological replicates were analyzed for each HSC subpopulation. Lower-SP and upper-SP HSCs were purified from three pools of mice on separate days. HSCs were further purified with the addition of canonical HSC makers; Sca-1+ c-Kit+ Lineage-