Hemopoietic stem cell reconstitution from mouse strains differing greatly in leukocyte production

Bone marrow cells or fetal liver cells from two strains of mice genetically different in leukocyte counts were injected into lethally irradiated F1 hybrids. The F1 mice which received bone marrow cells from the high leukocyte count (HLC) strain had sigificantly higher leukocyte counts than those which received marrow cells from the low leukocyte count (LLC) strain. Similar differences, although smaller, were found when fetal liver cells were injected. We tentatively conclude that the genetic characteristics of differentiation and proliferation of the hemopoietic stem cells are traits intrinsic to the cell, which remain essentially unaffected by the extracellular environment.