Figure 1. Synaptotagmin-7 expression in glucagon-secreting cells.

Twenty micrometre pancreatic sections were stained with antibodies against synaptotagmin-7 (S757, Synaptic Systems) and glucagon, followed by fluorescence-conjugated secondary antibodies. Representative images of such stained sections, taken on a Leica TCS2 confocal microscope, are shown. Synaptotagmin-7 (Syt 7, red) was expressed in glucagon-positive cells and shown to have a high degree of overlap with glucagon signals (green). Arrows indicate selected overlapping signals of synaptotagmin-7 and glucagon. For comparison, no apparent synaptotagmin-7 signal was detected in islet sections from synaptotagmin-7 KO (Syt7^−/−) mouse. Scale bars: 40, 20 and 5 μm for top, middle and bottom rows, respectively.