SEAN MORRISON, PH.D., is a researcher at the University of Michigan who examines different properties of stem cells from different tissues, namely the precursors of hematopoietic (blood and immune) cells and cells of the peripheral nervous system. Stem cells are cells that are at the top of the differentiation line; developing from these primitive cells are all types of cells in that certain tissue. Morrison and his lab investigate the intrinsic regulatory mechanisms of these stem cells, focusing specifically on cell self—renewal and cell aging. They are looking to see whether critical mechanisms are conserved between different stem cell lines, that is, do cells from the hematopoietic precursors and nervous cell precursors have similar cellular processes? A general answer the researchers have come up with ...