Figure 7.

(A) The chromatin surrounding the segregated nucleolus showed characteristics of heterochromatin via staining with an antibody against dimethylated lysine 9 of histone H3, but not with the euochromatin marker: dimethyled lysine 4 of histone H3. Bar, 5 μm. (B) Chromosome labeling by DNA FISH showed that peripheral chromosomes (3, 4) retained this positioning during transcriptional arrest, whereas NOR-containing chromosomes (15, 22) remained associated with the nucleolar region. In many cells, NOR containing chromosome 13 was not associated with nucleolar region after transcriptional arrest. Chromosome X was not associated with the nucleolus either. Bar, 10 μm