Figure 4

Expression of the ASS-EGFP reporter gene in adult transgenic mice. (A) Gross anatomy displaying EGFP fluorescence. Male mice of 3.5 month-old Tg (ASS-Ex3-EGFP) 3G line were sacrificed to display the internal organs. Images after peritoneal wall incision (left panel) and after gastrointestinal tract removal (middle panel) were acquired with a Canon PowerShot G11 digital camera built with blue filter. Fluorescence images were taken with an exposure time of 2 seconds. Right panel, comparison of fluorescence signals among the mouse lines. The abbreviated mouse designations are as described in the legend to Figure 1. non-Tg: a non-transgenic control. Images were taken with an exposure time of 4 seconds. (B) Study of EGFP fluorescence in (a) brain, (b) spleen and pancreas, (c) lung and heart, (d) salivary gland and (e) male urogenital system of the 3G line. Panels (i) and (ii) are whole-mount specimens examined under white and fluorescent light of a dissecting microscope, respectively. The rest of the panels were frozen sections examined by fluorescence microscopy. Top panel of (b) (iv) is a fluorescence image and the bottom one is that stained with DAPI. Panel (iv) of (e) is a higher magnification view of the testis counterstained with DAPI to show location of the interstitial tissue and seminiferous tubule. (C) Northern blot analysis. Left panel, detection of EGFP RNA expression in tissues of 3.5-month-old mice using an EGFP probe. The lane at the far right was RNA from a non-transgenic liver. The bottom lane was an analysis of Ass mRNA from a wild-type mouse using an ASS cDNA probe. Right panel, analysis of mouse Ass RNA and human ASS RNA in tissues of 27-day-old mice of the Tg (ASS-Ex16-EGFP) lines using an ASS cDNA probe. Lines 16H, 16 F and 16E carry 2, 5 and 10 transgene copies, respectively.