Fluorescence in situ hybridization of 5 S (red) and 35 S rDNA (green) probes to Helichrysum bracteatum nuclei. Pictures in the first row (A, B & C) show rDNA signals in interphase: (field 1), metaphase chromosomes (field 2), and a prophasic cell (field 3). The second row (D, E & F) shows late anaphase/early telophase. One rDNA homolog is highly condensed (arrowheads) whereas the other is spread throughout the nucleus and decondensed. Bar – 10 μm.