Figure 4
Endocrine cell transdifferentiation is islet autonomous. Photomicrographs of pancreas sections from lineage tracing mice killed 38 days following alloxan plus caerulein. (a) An islet with no preexisting β-cells (blue cytoplasmic insulin and red mT membrane fluorescence), demonstrating neogenic β-cells (blue cytoplasmic insulin and green eGFP membrane fluorescence; high-power views in b and c, neogenic cells marked with cyan arrowheads). (d) An islet with many preexisting β-cells (high-power views in e and f, preexisting cells marked with yellow arrowheads) demonstrating no neogenic β- or δ-cells. (g) Quantification of neogenic β- and δ- cells per islet. The number of preexisting β-cells in each islet (insulin+, mT+) was plotted against the number of neogenic β- plus δ-cells (insulin or somatostatin+, eGFP+) in that islet. The P-value for the difference between islets in which there were greater than 10 preexisting β-cells and at least one eGFP-positive cell expressing insulin or somatostatin (quadrant 2) versus islets in which there were ten or fewer β-cells expressing mT and at least one eGFP-positive cell expressing insulin or somatostatin (quadrant 4) was 0.0016, calculated using a two sample proportion test with continuity correction in R. Scale bar for b–f=10 μm
