Chromatin Profiling by Western Blot

Western blot analysis of equal amounts of crosslinked chromatin extracts or of histone extracts (see Supplemetary Methods) was performed as described^{25 (link)}. Antibodies used for western blot analysis are the following: anti-H3K27ac (ab4729, Abcam), anti-H3K27me3 (07-449, Millipore), 8WG16 (05-952, Millipore), anti-elongating RNA pol II (ab5095, Abcam), anti-Lamin B1 (ab65986, Abcam), anti-histone 4 (ab10158, Abcam), and anti-histone3 (ab1791, Abcam). Dilutions of antibodies were performed according to the manufacturer's guidelines. Time for analysis is indicated in the figures (Fig. 4b; Supplementary Fig. 4a, b; Supplementary Fig. 3c, d). Uncropped scans of all western blot figures are supplied in the Source Data file.