Fig. 4

Transmission electron microscopy (TEM) analysis. A and B Cryo-TEM of recombinant bacteria containing either pNZ-HTC or the empty vector (C-). A. TEM of HTC bacteria displayed the presence of vesicle near the plasma membrane. B TEM of C- bacteria. Scale = 100 nm (A and B). C and D Immunolabelling of bacteria harboring either HTC (C) or the empty vector (C-; D). Scale = 100 nm. E. Distribution of diameters of intracellular caveolin-1β enriched vesicles determined from TEM images (n = 390; N = 2); the orange region depicts the 75% most frequent values. F Negative staining-TEM images from vesicles isolated through density discontinuous gradient fraction F15 (scale = 200 nm). P = peptidoglycan, M = plasma membrane, Cy = cytoplasm