c-fms expressing cells in development

Through the developing embryo there are numerous phagocytic cells that can be detected by whole mount in situ hybridisation to localise macropohage-specific genes like c-fms, the receptor for macrophage colony-stimulating factor. This is a section of such a whole mount, around 11 days of development, showing that each little spot seen in a whole mount picture is actually an individual blue cell, and also giving a view of the numbers of such cells in the tissue even at this early stage of development. The numbers increase significantly from this point. Lichanska, A.M., Browne, C.M., Henkel, G.W., Murphy, K.M., Ostrowski, M.C., McKercher, S.R., Maki, R.A. & Hume, D.A. (1999) Differentiation of the embryonic mononuclear phagocyte system. The role of transcription factor PU.1. Blood I94:127-138