(A) Scheme for tracing intestinal progenitor cell number regulation in midgut with low intestinal renewal ('Low') using the lineage tracing ReDDM system. The strategy relies on minimizing exposure of flies to contaminated food by transferring flies to fresh food vials every two days ('Low') as compared with normal culturing conditions in which flies are typically transferred to fresh food vial every week. This 'Low' demand strategy effectively minimized intestinal renewal. 