(G) Confocal microscopy images of nuclei assembled for 120 min in mock depleted, Nup50 depleted (∆Nup50), and Nup50 depleted Xenopus egg extracts supplemented with recombinant Xenopus wild-type Nup50 or RCC1 binding mutants. Nuclei were fixed in 4 % PFA and 0.5 % glutaraldehyde, stained for NPCs (mAB414) and the chromatin (DAPI). Scale bar: 10 µm. Quantitation shows the average percentage of mAB414 positive nuclei for 100 randomly chosen chromatin substrates in each of three independent experiments. Individual data points are indicated (H) Confocal microscopy images of nuclei assembled for 120 min in mock depleted, Nup50 depleted (∆Nup50), and Nup50 depleted Xenopus egg extracts supplemented with RCC1 excess as indicated. Nuclei were fixed in 4 % PFA and 0.5 % glutaraldehyde, stained for NPCs (mAB414) and the chromatin (DAPI). Scale bar: 10 µm. Quantitation shows the average percentage of mAB414 positive nuclei for 100 randomly chosen chromatin substrates in each of three independent experiments. Individual data points are indicated. 