Figure 3: Longitudinal imaging of colorectal tumorigenesis.

(a–c) Fluorescence image of colorectal vasculature in a floxed Apc mouse at 11 weeks (a) and 13 weeks (b) after adeno-Cre administration, and of a large lesion at week 17 in another adeno-Cre–treated mouse (c). (d) Fluorescence images of Apc-knockout GFP⁺ cells (green) and blood vessels (red) at the same site in the descending colon, observed at days 10, 12, 14 and 28. Each image is a projection view of 50-μm z-dimension stack. The images show a GFP⁺ lesion that appeared to grow (*). Other GFP⁺ nodules shrunk (arrowhead) or vanished at day 28 (dashed circle). Blood vessels were visualized by intravenously injected FITC-dextran in a–c and by tetramethylrhodamine (TAMRA)-dextran in d. Scale bars, 200 μm.