Fig. 5.

Intestinal stem cell. (A) The three distinct segments of the Drosophila intestine: foregut, midgut and hindgut. (B) The midgut stem cells and their derivatives. Notch signaling promotes asymmetric division of intestinal stem cells (ISCs) to form enteroblasts (EBs). ISCs express the Notch ligand Delta (Dl), which activates Notch (N) in the EBs. Wingless (Wg) and Vein (Vn) are secreted from the visceral muscle and promote ISC maintenance and proliferation. BM, basement membrane; VM, visceral muscle; EE, enteroendocrine cell; EC, enterocyte.