Similarly, 37 transcription start sites in 32 genes contain RDac while 167 transcription start sites in 131 genes do not contain RDac. There was a significant enrichment of hyperacetylated RDac (regions in which the high maternal care group has higher acetylation levels) inside exons, particularly the first and last exons (P = 0.0014 and P = 0.0088, respectively; permutation test), and a significant depletion of hypoacetylated RDac inside the first and last exons (P = 0.0002 and P = 0.19, respectively; permutation test). RDac are relatively depleted in the 5′ and 3′ ends of genes (P = 0.02 by permutation test), likely reflecting the aforementioned depletion of nucleosomes at these sites in actively transcribed genes. In contrast, RDme co-localize in regulatory elements, particularly in the 5′ and 3′ ends of genes (P = 0.0032 by permutation test). Hypermethylated RDme (regions that are more methylated in the high maternal group than in the low maternal care group) are significantly enriched inside both the first and last exons of genes (P = 0.0008 and P = 0.004, respectively; permutation test) whereas hypomethylated RDme are significantly depleted inside the first exon (P = 0.0022; permutation test; Fig. 3b – red for hypermethylated RDme
