Transcriptionally Repressive Chromatin Remodelling and CpG Methylation in the Presence of Expanded CTG-Repeats at the DM1 Locus
Figure 2
CpG methylation increases with CTG-repeat length. (a) Schematic drawing of the position of the amplicons obtained with seminested PCR, used for bisulfite sequencing, relative to both CTCF-binding sites, the CTG-repeat and exon 15, in the 3′ region of the DMPK transgene. (b) CpG methylation in hearts of adult mice increases with expanding CTG-repeat length. For each repeat length category, 4 mice were used, and per mouse at least 10 clones were sequenced after bisulfite conversion. CpGs are numbered from 5′ to 3′. Shaded CpG numbers lie within the CTCF-binding site recognition sequence. Underlined CpG numbers are CpG dinucleotides that contain G residues essential for recognition by CTCF [19]. Numbers indicate the weighted average percentage of methylation at a particular CpG, seen across all clones in all 4 mice. Colour coding further indicates the approximate degree of methylation at a given CpG. (c) Example of methylation profiles obtained in different clones, representing different cardiac cells of 1 mouse per repeat length category. Individual clones show substantially distinct methylation patterns.
