Stem cell autotomy and niche interaction in different systems

Figure 9 Erythropoiesis in mammal bone marrow (schematized). The erythroblastic island consists of a central macrophage (MA) that functions as the niche, and the peripheral erythroblasts (EB), that represent stem/progenitor cells. Erythroblasts undergo an enucleation process (arrow) that results in the pyrenocyte (PC) that mainly consists of the erythroblast nucleus, and the nucleus-free reticulocyte (RC). The pyrenocyte is phagocytized by the macrophage (PH, phagosome), whereas the reticulocyte develops to the erythrocyte (EC) (adapted from Chasis et al[4]; Keerthivasan et al[98]).