Fig. 2: Disruption of GCGR increases glucagon mRNA and protein levels in α cells.

a Violin and t-SNE plots illustrating the expression levels and distribution of Gcg mRNA in α cells. b Violin plot depicting Gcg expression across different α-cell subclusters. In a and b, the whiskers indicated the maximum and minimum values, the center indicated the median and the bound of the box indicated upper and lower quartiles. c Representative confocal microscopy images of pancreatic sections stained with anti-glucagon antibody. Scale bar, 50 μm. d Quantification of the average single α-cell area (WT, n = 4 mice; GCGR-KO, n = 4 mice). e Quantification of glucagon fluorescence intensity per α cell (WT, n = 4 mice; GCGR-KO, n = 4 mice). f, g Representative TEM images of α-cells from WT and GCGR-KO islets. Yellow dotted lines indicate cell boundaries, and gray or black dots indicate the glucagon granules. Scale bar, 5 μm. h Quantification of the number of glucagon granules per α cell, normalized to cell area. (WT, n = 3 mice; GCGR-KO, n = 3 mice). i Quantification of individual glucagon granule area (WT, n = 3 mice; GCGR-KO, n = 3 mice). j Density curve of individual glucagon granule areas (WT, n = 2313 granules; GCGR-KO, n = 3289 granules). Data presented in (d, e, h, i) are mean ± SEM, analyzed by an unpaired two-tailed t-test. p-values < 0.05 are displayed. Source data are provided as a Source Data file.