Co-factors bind few of their available motifs at monomodal or low H3K4me1 sites. Venn diagrams showing the number of loci shared by (A) PDX1 and FOXA2 in islets or (B) FOXA2 and HNF4A in the liver. (C) Fraction of co-bound islet sites (FOXA2–PDX1) versus FOXA2 (FOXA2) only, or PDX1 (PDX1) only sites that have bimodal, monomodal, or low H3K4me1 profiles. (D) Fraction of co-bound liver sites (FOXA2–HNF4A) versus FOXA2 (FOXA2) only or HNF4A (HNF4A) only sites that have bimodal, monomodal, or low H3K4me1 profiles. (E) Fraction of bimodal, monomodal, or low H3K4me1 sites in the FOXA2 (islet and liver), PDX1, and HNF4A peak sets that contain a motif for the indicated transcription factors. (F) The fraction of sites that contain a motif for a potential TF binding partner (FOXA2 with PDX1 in islets and FOXA2 with HNF4A in liver) actually co-bound in the bimodal, monomodal, or low H3K4me1 peak sets.
