Electron tomography reveals numerous connections between the Golgi apparatus and WPBs found after 4 hours of transfection. Example of a WPB 4 hours after transfection displaying numerous connections to the Golgi when analyzed by electron tomography. The WPB was localized using CLEM. (A) Two-dimensional image of an immature WPB that was observed in close proximity to the Golgi. (B-C) Tomogram sections showing the connections (arrows) to the Golgi. Also note that the membrane that is not associating with the Golgi is coated by clathrin (arrowheads). (D) A 3-dimensional model of the forming WPB (green) showing the numerous connections (arrows). (E) The addition of a 3-dimensional representation of the Golgi (light yellow) reveals its complex organization around the forming WPB (green). See also supplemental Video 1. Scale bars: (A-B) 250 nm. Electron micrographs and tilt series for tomography were acquired using an FEI Tecnai 12 at 120 kV and using an FEI Eagle 4k × 4k CCD camera. Tilt series for tomography were collected with SerialEM. Tomogram reconstructions were performed in IMOD. Segmentation was performed in Amira (Visualization Sciences Group, FEI). Go, Golgi.