A
Drosophila posterior midgut epithelium. Schematic representation of cell types and their lineage relationships (see text for details; Micchelli & Perrimon,
2006; Ohlstein & Spradling,
2006). Intestinal stem cells (ISCs) and enteroblasts (EBs) can be usually identified by an
esg-GFP reporter, or expression of GFP under control of ISC/EB-specific drivers. ISCs express Delta (Dl, which results in a characteristic punctate staining of ISCs), which activates Notch in EBs (revealed by β-GAL staining of flies that carry a
Su(H)-lacZ reporter of Notch activity (Bray & Furriols,
2001)). Enteroendocrine cells (EE) are identified by nuclear Prospero (Pros) staining, whereas enterocytes (ECs) can be distinguished based on their large polyploidy nuclei (as revealed by DAPI staining of DNA).