CLEM confirming AL formation in the IC but not surrounding lagging chromosomes in an U2OS siELYScell (as in C). Top panels, enlarged dotted white boxed region showing overlapping ER membrane and NPC signals in the IC; EM showing ALs in the NE-adjacent ER membrane (arrowheads), three serial EM z sections, left to right. Bottom panels, same as top for a region surrounding the lagging chromosome. Note: EM images in the bottom row correspond to the dotted yellow boxed region. Images: single focal plane; time: minutes:seconds; DNA: SiR-DNA; scale bars: 5 μm. Quantifications:****p < 0.0001,***p = 0.0001, two-tailed Mann-Whitney tests; error bars: mean with 95% CI.
