Figure 4. OGFOD1 knockdown results in DNA compaction.

(A) Western blot analysis of methylation states of H4K20 in OGFOD1 knockdown MDA-MB-231 cells. Nuclear fraction was stained with antibodies against methylated H4K20. (B) Immunofluorescence staining of methylated H4K20 in OGFOD1 knockdown cells. Mono-, di, and trimethylated H4K20 was stained with the corresponding antibodies (red). Nuclei were stained with DAPI. (C) OGFOD1 knockdown cells were synchronized with double thymidine and released by adding serum. At each cell cycle phase (late S; 5 hours, M; 6.5 hours), cells were harvested and probed with the indicated antibodies. (D) Measurement of DNA compaction by dual-color fluorescence in situ hybridization. Fixed cells were labeled with probes for 16p13.11 (green) and 16q22.1 (red). Distances between 2 probes were measured as described in Materials and Methods. P-value was calculated by student t-test (P < 0.0005).