Allele-specific positioning of nucleosomes at MLH1 variants. (A) The MLH1 gene with arrows showing the location of the splice site mutations investigated in the LCLs derived from the six patients. The numbers correspond to the NOMe-seq assays shown in panel B (exon, vertical bar; intron, horizontal bar with arrows). (B) Each panel shows the nucleosome occupancy on the wild-type allele (upper) and the allele harbouring the indicated splice site mutation (lower). Blue box = exon; blue arrows = intron and direction of transcription; yellow diamond = location of splice site mutation; vertical black bars below line = GpC sites; vertical black bars above line = CpG sites; the pink bar represents a single nucleosome (150 bp, drawn to scale); pink shading indicates the location of nucleosomes on individual DNA molecules as determined by GpC methyltransferase inaccessibility; black circles = methylated GpC/accessible to M.Cvi PI; white circles = unmethylated GpC/inaccessible to M.Cvi PI. CpG sites are depicted by triangles. Black triangle = methylated CpG; white triangle = unmethylated CpG.