Figure A7.

Mapping of epigenetic modifiers into gene expression SOM (see also Figure 5b). Methyltransferases (red frames) and demethylases (blue frames) for part of modifications accumulate in different regions of the map referring to their activation in different phases of lifetime. Particularly, H3K4me3 writers show often high expression in early and intermediate phases of lifetime possibly reflecting transcriptional activation of the associated genes. For writers of the repressive H3K27me3 marks this relation reverses, i.e., writers activate with delay to erasers. A similar but smaller delay is observed for writers of DNA methylation, which also associate with repression of gene expression. Hence, modifications activating transcription seem to precede repressive modifications for H3K4, H3K27, DNA and, to a lesser degree, H3K36. Note that SOM mapping of the respective genes reveals these subtle shifts not immediately evident from the aging profiles (Figure 5b,c).