Fig. 7

The N terminus of CTCF interacts with RAD21. a Schematic showing the doxycycline-inducible parent and chimeric protein transgenes knocked into the Tigre locus. b Flow cytometry confirms that the level of mRuby2 expression of the transgenes and parental proteins are comparable. c Western blot using FLAG antibody shows that the level of expression of CLL and LLC is comparable across experimental conditions (D versus ID). Histone H3 serves as loading control. d, e Heatmaps showing CTCFL, CLL, LLC, CLC, and CTCF ChIP-seq signals at regions where they bind in the presence (d) and absence (e) of endogenous CTCF. The heatmaps are divided into CTCF only, CTCF+CTCFL overlapping, and CTCFL-only sites. Average profile of the respective heatmaps is shown above the corresponding heatmaps. f Co-IP experiments showing interaction of RAD21 with transgenic CLL and LLC in the absence (ID) of CTCF. M stands for molecular weight marker and the corresponding weights are shown. g Insulation scores in boundaries of CTCF+CTCFL overlapping sites in CTCF-depleted cells (CTCF I) and cells depleted of CTCF that were induced to express transgenic CTCF and CLL (ID condition). h Aggregate peak analysis demonstrates the strength of the loops in the CTCF ID, CTCF I, and CLL ID conditions at sites where CTCF and CTCFL bind competitively. i Snapshot of Hi-C data from Juicebox showing TADs in the presence of transgenic CTCF (CTCF ID), loss of TADs after CTCF depletion (CTCF I), and partial recue of TADs when CLL was expressed in the absence of endogenous CTCF (CLL ID). The corresponding FLAG ChIPs are shown on the x- and y-axis