Additional file 2: Figure S2. BORIS binds at the same regulatory site as CTCF in rDNA. (A) The distribution of Chip-seq tags across the consensus rDNA repeat is shown for the input, CTCF ChIP-seq and BORIS ChIP-seq. The sites chosen for EMSA are indicated with brackets. (B) The corresponding structure of “canonical” rDNA repeat. The long arrow corresponds to the Pol I transcript; the short arrow—noncoding RNA; NTS—non-transcribed spacers. (C) EMSA of the chosen rDNA sites confirming that the known CTCF site in PolI promoter is co-occupied by CTCF in BORIS, while sampling of BORIS-only putative sites shows that there is no BORIS binding to these sites in vitro. (D) The assessment of CpG methylation for probe #3 used in (C) using the diagnostic digestion with Aci I endonuclease, before and after methylation.