Fig. 1.

Synaptotagmin-7 is present in mouse pancreatic β-cells. Twenty-micrometer pancreatic sections were first reacted with both a polyclonal rabbit antibody against synaptotagmin-7 (S757; Synaptic Systems) and a monoclonal guinea pig antibody against insulin, followed by fluorescence-conjugated secondary antibodies (Alexa Fluor 546 goat-anti-rabbit IgG and Alexa Fluor 488 Donkey-anti-Guinea Pig IgG). Representative images of such stained sections, taken on a Leica TCS2 confocal microscope, are shown. Synaptotagmin-7 (Syt7, red) was expressed in insulin-positive cells and shown to have high degree of overlap with insulin signals (green). Arrows indicate selected overlapping signals of insulin and synaptotagmin-7. For comparison, no apparent synaptotagmin-7 signal was detected in islet sections from synaptotagmin-7 mutant (Syt7^−/−) mouse. (Scale bars: 40, 20, and 5 μm for Upper, Middle, and Bottom, respectively.)