Figure 1.

The molecular markers expression and proliferation in cardia. (A,B) The cardia of a Stat92E-GFP fly was stained with GFP (green) and DAPI (blue). (B) The high magnification of (A). (C) The cardia of a Stat92E-GFP fly was stained with GFP (green) and Odd (red) antibodies. (D, D′) the cardia of a wg-Gal4 UAS-GFP fly was stained with GFP (green) and Ptc (red) antibodies and DAPI (blue). (D′) A high magnification picture of (D), in which a part of wg-Gal4 UAS-GFP and anti-Ptc co-localize (yellow—highlighted by blue dashed line). (E) The cardia of a Stat92E-GFP fly was analyzed after five days of BrdU pulse for cell proliferation. F/M junction cells outlined by a white dotted line; anti-GFP (green), anti-BrdU (red), and DAPI (blue). The red arrows show the cell proliferation at anterior midgut region, white arrow shows the cell proliferation at foregut region (F) The Stat92E-GFP-positive cells are proliferating at the F/M junction after five days of BrdU pulse and five days chase period. Only the Stat92E-GFP-positive F/M junction cells retain BrdU, outlined by a white dotted line; anti-GFP (green), anti-BrdU (red), and DAPI (blue). (G) The cardia of a Stat92E-GFP fly was analyzed after five days BrdU pulse and 17 days chase. All BrdU-labeled cells at the F/M junction were gone. The cardia was stained with anti-GFP (green), anti-BrdU (red), and DAPI (blue). The F/M junction cells are outlined by a white dotted line (H, H′) the wg-Gal4 UAS-GFP flies were stained with phospho-histone H3 antibody, which labels only a rare population of cell with small nuclei (highlighted in white box; anti-PH3, red; anti-GFP, green; and DAPI, blue). (I) wg-Gal4 UAS-GFP flies were stained with anti-GFP and Apoptag kit to detect dead cells. Anterior is at the top in all panels. Scale bars: 50 µm (A); 5 µm ( B, D′ H′); 10 µm (C, D, E, H, I); 20 µm (F, G).