Fig. 5.

Acute β-cell ablation in adults by MTZ immersion. (A) FBG readings from five groups of adult fish: untreated ins:mCherry NTR2.0^ir2018 fish (NTR control), wild-type fish immersed in 5 mM MTZ for 24 h (MTZ control), ins:mCherry NTR2.0^ir2018 fish immersed for either 24 h or 48 h in 5 mM MTZ (NTR2.0 5 mM MTZ 24 h or 48 h), and ins:mCherry NTR2.0^ir2018 fish immersed in 10 mM MTZ for 24 h (positive control). Owing to the limitation of the blood glucose meter used, 500 mg/dl is the maximum FBG reading that can be captured. (B) FBG readings of NTR2.0 control and ins:mCherry NTR2.0^ir2018 fish. The NTR2.0 fish were treated with 5 mM MTZ for 48 h and were then allowed to recover for either 3, 7 or 17 days, after which FBG measurements were taken. N.S., not significant; ***P<0.05 (unpaired two-tailed Student's t-test). (C-G) Confocal images of paraffin sections through the pancreas after immunofluorescent detection for the islet markers insulin (green) and glucagon (red). Nuclei were counterstained with DAPI (blue) (40×, scale bars: 10 µm). (H,I,J,K,L) H&E histological analysis of intestines from fish in each treatment group (20×, scale bars: 100 µm). (H′,I′,J′,K′,L′) Magnification of same images at 60× (scale bars: 50 µm). ctrl, control; D, day; FBG, fasting blood glucose; MTZ, metronidazole; NTR, nitroreductase.