COLONY-STIMULATING FACTOR-I EXPRESSION IS DEVELOPMENTALLY-REGULATED IN THE MOUSE

Colony stimulating factor-1 (CSF-1) regulates the survival, proliferat ion, and differentiation of mononuclear phagocytes. To determine wheth er CSF-1 plays a role in the perinatal development of these cells, CSF -1 protein and mRNA expression in tissues and serum from fetal/neonata l mice and their mothers was analyzed. As fetal/neonatal age increased , CSF-1 concentrations rose in liver, kidney, and lang, declined in br ain and serum, and did not change in intestine and heart, Concurrently , fetal/neonatal CSF-1 concentrations were higher in Liver, kidney, an d serum and lower in lung, brain, intestine, and heart than maternal t issue/serum concentrations, which showed no correlations with gestatio nal or post-partum stage, CSF-1 mRNA was detected in all tissues exami ned and its expression increased in lung and heart and decreased in br ain with increasing fetal/neonatal age. The developmental regulation o f mouse CSF-1 expression appears to be important for mononuclear phago cyte development during this period.