FIG. 6.
Disrupted heterochromatin structure in incompletely senescent Rb1ΔL/ΔL mutant cells. (A and B) ChIPs were performed on extracts from asynchronous or Ras-induced senescent MEFs. Sheared chromatin was precipitated with rabbit immunoglobulin G (IgG) control, anti-H3K9me3, or anti-H3K27me3 antibodies. An input control PCR was performed on 0.5% of the chromatin used for each ChIP. Precipitated DNA fragments were amplified by PCR using primers specific for the promoter regions of Airn, Hoxd10, Pcna, Ccne1, Ccna2, Mcm3, and Mcm5. Band intensities were quantified using image quantification software from Bio-Rad and are presented as graphs. Error bars indicate standard deviation from the mean value generated from multiple trials of ChIPs. TE, Tris-EDTA buffer.