CTCF-binding sites separate active and repressive domains. (A) CTCF-binding sites separate the chromatin domains marked by H3K27me3 and H2AK5ac in a 900-kb region in chromosome 1. The H3K27me3 and H2AK5ac loci are complementary to each other and appear to be separated by CTCF-binding sites (green bars). The active genes are shaded green and the silent genes are shaded pink. (Inset) The transition between the H3K27me3 and H2AK5ac domains separated by CTCF sites. (B) The H3K27me3 profiles were plotted surrounding the nonpromoter (at least 5 kb away from the promoter) CTCF-binding sites in CD4+ T cells. (BS) CTCF-binding site. Red line indicates the reads from the sense strand and green line indicates reads from the antisense strand of DNA. (C) The H2AK5ac profiles were plotted surrounding the nonpromoter CTCF-binding sites in CD4+ T cells. (BS) CTCF-binding site.
