Supplementary Figure 7: 3D structural comparison of chronologically ordered prepores and mature pores.

Electron tomographic slices of single (a) and averaged (b) pre- and mature pores at indicated time points are shown. No symmetry was imposed in averaging. The averaged images are from 72, 78, 86, 64, 58, 52 pores for 3.1, 3.9, 4.3, 5.3, 5.7, and 6.3 min, respectively. Red arrowheads i, ii, and iii on side-view images indicate the locations of the planes which are inclined at 90° in top views i, ii, and iii. Scale bars, 100 nm. (c) Quantification of the inner ring intensity. As in Fig. 4a, the region indicated by red dashed box in the left panel was Z-projected and the radial intensity from the center of the pore was measured. Intensity was normalized to that of NE lumen. The intensity in the region adjacent to the membrane as indicated by a green line in the left panels was quantified and plotted. The plot shows the mean from 71, 75, 88, 64, 58, and 52 pores at 4.8, 6.1, 7.7, 10, 15 min, and in interphase, respectively. A green line shows a sigmoid curve. For comparison, a sigmoid curve of pre-pore diameter in Fig. 2c is shown by a pink dashed line.