Fig. 5. Tsix-regulatory region shows SPEN, HDAC3 and H3K27ac enrichment.

a Genome browser tracks showing allele-specific SPEN, HDAC3, H3K27ac and H3K27me3 binding at the Xist–Tsix locus. The top part (dark) of each track represents the Xi and the bottom (light) the Xa. SPEN CUT&RUN (blue, top) profile in Xist-inducible undifferentiated ESCs (day 0) untreated or treated with doxycycline (24 h)²⁵. HDAC3 (green, middle–top) and H3K27ac ChIP-seq (yellow, middle–bottom) in Xist-inducible undifferentiated ESC (day 0) untreated or treated with doxycycline (24 h)²⁹. H3K27me3 ChIP-seq (red, bottom) in Wt and Spen^−/− ESCs at days 0 and 3 of monolayer differentiation. The light-blue rectangle highlights the Tsix regulatory region, including the Tsix minor and major promoters, and Xite. The light-gray rectangle highlights the H3K27me3 hotspot region. The dashed rectangle indicates the genomic region in (b). b Zoom-in view of the Tsix promoter region, showing the SPEN CUT&RUN profile in undifferentiated ESCs (day 0) untreated or treated (4 h, 8 h and 24 h) with doxycycline.