Fig. 6.

Nutritional regulation of Drosophila stem/progenitor cell systems. Nutrients (amino acids and fat/glucose) are sensed by the fat body, which relays the signals to the insulin-producing cells (IPCs) in the brain or to glial cells in the case of neuroblast development. Fat and glucose trigger Upd2 and amino acids trigger unknown factors (X) to stimulate the secretion of Dilps. Various Dilps circulate throughout the body and regulate stem and progenitor cells as well as their niche in the lymph gland and the male and female germline. The dashed arrow pointing to ISCs is based on the findings of O’Brien et al. (O’Brien et al., 2011). Stem cells/progenitors are in green and the niche in blue. FB, fat body; G, glial cells; NB, neuroblast.