Electron micrographs show larger but fewer LDCVs in the absence of dysbindin. (A) Representative electron micrographs of adrenal sections from WT (left) and sdy (right) mice. LDCVs dispersed throughout the cytoplasm in both cell types. (insets) Single morphologically docked vesicles. Bars: (top) 2 μm; (bottom) 500 nm; (insets) 400 nm. (B) Distribution of vesicle diameters shows larger vesicles in sdy cells (black) than in WT (gray). Single Gaussian fittings of the distribution are superimposed on the bar graphs. Mean vesicle diameters were 214 ± 2 nm in the WT and 238 ± 2 nm in sdy (bottom). n = 973 (WT) and 1,095 vesicles (sdy). (C) Histogram shows that the lack of dysbindin (sdy) leads to a reduced number of LDCVs per μm² as compared with WT cells. WT, 6.6 ± 0.2 vesicles per μm² (21 cells from two WT mice); sdy, 4.9 ± 0.1 vesicles per μm² (19 cells from three sdy mice). (D) Distribution of distance between vesicle membrane and plasma membrane. Vesicles located within 100 nm from the plasma membrane were defined as docked vesicles. ***, P < 0.001. Error bars indicate the mean ± SEM.