Three-dimensional fluorescent in situ hybridization (3D FISH) performed on 1-cell SCNT embryos that developed until 10 hpa in the absence (a. CTRL) or presence (b. TSA) of TSA. FISH signals of pericentric and centromeric repeats are displayed in red and green, respectively, with DNA counterstaining in blue. Note the close but distinct apposition of the centromeric and pericentric signals. Arrows point to centromeres not associated with NPB peripheries. Scale bars, 5 μm.