Figure 2

EGFP expression during liver development in the transgenic mice. (A) Observing EGFP fluorescence under a fluorescence dissecting microscope. Liver samples taken from fetal stages (E14.5-E17.5), 1 day to 7 day (D1-D7) and 1 to 4 week (1 W-4 W) after birth were examined directly under a fluorescence dissecting microscope. 3G, 3J, 16E, 16 F, WT represent Tg(ASS-Ex3-EGFP) 3GTsu, Tg(ASS-Ex3-EGFP) 3JTsu, Tg(ASS-Ex16-EGFP) 16ETsu, Tg(ASS-Ex16-EGFP) 16FTsu and wild-type mouse lines, respectively. Images were taken with an exposure time of 4 seconds except for 3G line with 1 second. Images in the bottom panel of fetal stage of 3G line were taken with exposure time of 4 seconds. Images were captured with magnification of 1.25-fold for samples at E14.5 to D7 and 0.7-fold for W1 to W4. Images D7 and W1 were taken from an identical sample. Each grid is 1 mm. (B) Comparison of liver zonation patterns among mouse lines. Liver frozen sections taken from 1- to 4-week transgenic lines and wild type were examined by fluorescence microscopy. Exposure time of the images was 50 ms except for 3G of 1 ms. Scale bar, 200 μm. (C) Study of EGFP fluorescence pattern in cryosections. Mouse liver sections were fixed and embedded in OCT compound. Serial frozen sections were examined by fluorescence microscopy. Left bottom panel was sections stained by DAPI. The liver stage and mouse line employed are as indicated. Scale bar, 200 μm.