Induced Expression of c-fms in Normal Hematopoietic Cells Shows Evidence for Both Conservation and Lineage Restriction of Signal Transduction

Retrovirus-mediated gene transfer was used to obtain expression of the macrophage colony-stimulating factor (MCSF) receptor, c-fms, on hematopoietic lineages that normally do not express this receptor. Cultures ofmurine fetal liver cells infected with the c-fms retrovirus developed erythroid colonies in cultures stimulated with M-CSF. However, these colonies were fewer and less hemoglobinised than colonies in parallel cultures stimulated by erythropoietin. Culture of isolated clones demonstrated a direct action of M-CSF on erythroid clones. Culture of c-fms retrovirus-infected adult murine bone marrow cells showed