Fig. 1.

In vivo bioluminescence imaging of mice expressing luciferase under control of the mouse insulin I promoter detects light emission from the pancreas. a A MIP-Luc-VU transgenic mouse, but not control mouse, emitted light after administration of the luciferin substrate in an anatomical region consistent with the pancreas. b After injection of luciferin, the abdominal cavity was immediately opened to expose the pancreas and verify that all light emission was emanating from the pancreas; no other organs emitted light. c A MIP-Luc-VU mouse placed in a right lateral decubitis position displayed light emission from the pancreatic region. Regions of interest drawn over the bioluminescent region demonstrate the manner in which bioluminescence emission was quantified. d Three-dimensional reconstruction of bioluminescence from the pancreas of a MIP-Luc-VU mouse. Clusters of bioluminescent islets are reconstructed as red voxels within the volume of the mouse. The surface projection from the bioluminescent islets is displayed on the rainbow color scale. BLI in MIP-Luc-VU mice was similar in males and females and between mice of different generations and ages. There was no statistically significant difference between age-matched male and female control mice used in these studies (P=0.199, unpaired t test) used for subsequent STZ and high-fat diet experiments. The mice used in the STZ experiment and high-fat diet came from successive generations of MIP-Luc-VU mice. There was no significant difference between the STZ control cohort (four mice, approximately 60 islets/mouse) and high-fat control cohort (three mice) as determined by unpaired t test (P=0.5654). The control mice used in the high-fat diet were imaged at 1, 3, and 6 months of age and there was no significant difference in bioluminescence intensity as determined by ANOVA.