Impaired insulin granule trafficking in FAK-deficient β-cells leads to a lower number of docked insulin granules. A: Electron micrographs of β-cell sections. Scale bar, 500 nm. Black dashed lines indicate a distance of 200 nm from the plasma
membrane, showing that β-cells of RIPcre+fakfl/fl mice have a fewer number of insulin granules docked at the plasma membrane in both saline-treated or glucose-treated (15
mmol/L) conditions. B: Quantification of relative granule distribution and density in the first 2-μm region adjacent to the plasma membrane; n = ∼2,000 insulin granules from 12–15 β-cells were counted from three mice per genotype. *Comparison between saline-treated
RIPcre+fak+/+ and RIPcre+fakfl/fl islets. #Comparison between glucose-treated RIPcre+fak+/+ and RIPcre+fakfl/fl islets. *,#P < 0.05; ##P < 0.01. Results represent mean ± SE. All mice used in experiments were between 4 and 8 weeks of age. +,+/+, RIPcre+fak+/+; +,−/−, RIPcre+fakfl/fl.