Fig. 4. Localization of repetitive sequences in cells cultured for 120 hours. DAPI staining (left column); FISH signal (middle column); merge (right column). (A) 45S rDNA (green signal) is condensed and located at large chromocenters. (B-D) FISH signals of the 180 bp repeat (red) and 5S rDNA (green) show partial (B,C) to full (D) condensation at chromocenters. Note that partially condensed 180 bp repeats colocalize with faint chromocenters (arrowheads in B). The large chromocenters (arrows) contain 45S repeats. (E,F) BAC F28D6 (E) and the Athila transposon (F) are only partially localized at chromocenters. Bar, 5 µm.