NUP153 topography during mitosis.

<p><b>A1-A4</b> and <b>B1-B4.</b> Projections of SIM serial sections through metaphase cells of 2-cell embryos stained with DAPI (A1, B1) and immunostained for lamin B (A2, B2) and NUP153 (A3, B3). A4 and B4 show merged images with DAPI (grey), lamin B (green) and NUP153 (red). <b>C1-C4.</b> 3D reconstructions of SIM serial sections recorded from an anaphase cell of a 2-cell embryo; DAPI (C1), lamin B (C2), NUP153 (C3), merged image (C4) color-coded as above. 3D reconstructions were rotated in order to provide a view on the two separating anaphase rosettes, which overlapped each other in the original position. Granular lamin B was enriched along the entire mitotic spindle in metaphase and anaphase cells (compare B2 and B4 with C2 and C4). In <b>A5, B5</b> and <b>C5</b> the metaphase plates (A1, B1) and anaphase rosettes (C1) are presented with seven color-coded DAPI intensity classes. DAPI intensities below the chosen threshold are attributed to class 1 (blue), pixels representing increasing DAPI intensities are color-coded with dark and light red (classes 2 and 3), orange (class 4), dark and light yellow (classes 5 and 6) and white (class 7). NUP153 signals are displayed in black. <b>A6, B6</b> and <b>C6</b> present enlargements of boxed areas in A5, B5 and C5 with black NUP153 signals. <b>B7</b> and <b>C7</b> show the same areas as B6 and C6, respectively, without NUP153 signals. A7, B8 and C8 show relative NUP153 accumulations and depletions, respectively, calculated for all seven DAPI classes. In the three mitotic cells the relative numbers of NUP153 positive pixels were significantly enriched in chromatids as compared to the cytoplasm (represented by class 1) (p <10^-15). NUP153 was mostly overrepresented in the periphery of chromatids (classes 2 and 3). In the innermost area of chromatids (class 7) NUP153 was reduced compared with the chromatin periphery (p <10^-15), but still significantly enriched in comparison with the cytoplasm (p <10^-15). Bars: 5 μm for A1-A5, B1-B5, C1-C5; 2 μm for A6, B6 and B7, C6 and C7.