Graphical representation of the erythroblastic island, which consists of a central macrophage, surrounded by developing erythroid progenitors. The latter are bound to the macrophage via adhesion molecules, such as VLA-4 (on the erythroid cells) and VCAM-1 (on the macrophage) and erythroblast macrophage protein. The macrophage provides iron from ferritin stores to the erythroid cells, which is needed for hemoglobin production. Macrophages also phagocytize expelled nuclei (pyrenocytes) and organelles.
Image created by Dr. Behling-Kelly
