Fig. 2. Association of membrane vesicles with manually isolated stage III-IV GV envelopes. Whole GVs were manually isolated from stage III-IV Xenopus oocytes and prepared for either feSEM microscopy (a,c) or thin-section TEM (b). Arrowheads show large vesicles and arrows show small smooth vesicles in panel a. In thin-section TEM, vesicles that were close to (arrow), attached to (arrowheads) or fused with the ONM (*) are shown in panel b. NPC intermediates (arrowheads) that appear at high density in the vicinity of areas of membrane fusion are illustrated in panel c. Samples were prepared for immunogold labelling with either CEL13A (NEP-A, panels d,e) or antibody against XLAP2 (NEP-B, panels f,g). Panels d and f show the ONM, whereas panels e and g show the INM. In the micrographs, individual gold particles (appearing black) have been artificially highlighted with white rings to improve their visibility. CEL13A decorated a range of vesicles varying in diameter from 100–500 nm, as well as the ONM. Antibodies against XLAP2 decorated the INM and to some extent the ONM but did not decorate any of the vesicles. Bars, 1000 nm (a); 200 nm (b); 100 nm (c-g).