[Formation of foci of myeloid cells on colonies of thymus and bone marrow fibroblasts in monolayer cultures].

A culture system favouring myeloid cell formation directly on the surface of mouse stromal fibroblast colonies has been developed. It has been shown that the plaques formed are both much more numerous and essentially larger on stromal fibroblast colonies of thymus than of bone marrow origin. Consequently, hemopoietic precursor cells that form the myeloid plaques in the monolayer cultures interact dissimilarly with stromal mechanocytes of different origin.