ΔCDK-RB induces dispersion and scattering in both heterochromatin and euchromatin regions. (A and E) Images of foci categorized as compact, diffused, and dispersed detected using probes to chromosome 7 and chromosome 6 α-satellite heterochromatin. Skeleton signals are shown in inset. (B and F) Percentage of foci in each category and mean skeleton dot length for these heterochromatin regions. (C and G) Images of foci categorized as compact/diffused, dispersed, and scattered detected using probes to 19q13.42 and 19q13.2. Skeleton signals are shown in inset. (D and H) Scatter plots depicting distribution of individual skeleton dot lengths and percentage of foci in each category for these regions of euchromatin. Note that ΔCDK-RB–expressing cells have significantly higher mean skeleton dot lengths, shifted-up distribution of skeleton dot lengths, and significantly higher percentages of cells with dispersed/scattered foci. Quantitation is from two independent biological replicates, set up and performed on different days. (I) Number of RB- and E2F-bound peaks per 100 kb in the four tested regions. RB- or E2F-bound chromatin loci were detected only in the two euchromatin regions. Numbers of foci quantified for each sample (n) are as follows (in the order they appear on the bar graphs): B, n = 112, 84; D, n = 72, 97; F, n = 66, 59; H, n = 191, 137. Error bars are SEM. For B, D, F, and H (left panels), asterisks denote P values from nonparametric two-tailed Mann–Whitney U test. For B, D, F, and H (right panels), asterisks denote P values from nonparametric two-tailed multiple t test (without correction for multiple comparisons). ns, P > 0.05; *, P ≤ 0.05; **, P ≤ 0.01; ***, P ≤ 0.001; ****, P ≤ 0.0001. Scale bar (including insets) = 2 µm. Dashed lines indicate the cutoffs for defining the categories compact, diffused, and dispersed for chromosome 7 α-satellite and chromosome 6 α-satellite and compact/diffused, dispersed, and scattered for 19q13.42 and 19q13.2 probe.