In situ hybridization analysis suggests specific expression of HAL2 in the proliferating adult intestinal progenitor/stem cells. ISH on intestinal cross-sections at stages 54 (A), 61 (B), and 66 (C) was carried out with anti-sense probe for HAL2. An enlarged photo of the boxed areas (a, b, c) in the top panels are shown in the lower panels. Note that HAL2 staining was found to be in clusters of cells located in between the dying larval epithelial cells and connective tissue at the climax of metamorphosis, where the proliferating adult epithelial cells are located [8, 19, 36, 48], consistent with the expression data in Figures 3 and 4. AE, adult epithelium; CT, connective tissue; Lu, lumen; LE, larval epithelium; M, muscle; Ty, typhlosole.