Expression of macrophage colony-stimulating factor gene in the mouse brain during development

Abstract
We have investigated the expression of macrophagecolony stimulating factor (M‐CSF) gene in mouse brain during development. Northern blot analysis of cerebral RNA evidenced a 4.5‐kb M‐CSF transcript from day 14 of gestation until 2 weeks after birth. The cell type responsible for this transcription was studied using in vitro cell cultures. The 4.5‐kb M‐CSF transcript was found both in astrocyte primary cultures and in immortalized astrocytic cell lines. M‐CSF mRNA was also detected in lipopolysaccharide‐stimulated brain macrophage cultures. These results suggest that M‐CSF is involved in the outgrowth of microglia during ontogenesis.