FIGURE 1.

Summary of epigenetic processes that can occur in the mammalian central nervous system. (A) DNA modifying proteins can methylate CG of CH dinucleotides. Methylated cytosines can be further modified to 5hmC, 5fC, or 5caC to be replaced with an unmodified cytosine through thymine DNA glycosylase, TDG. (B) Histone modifiers can add various groups to the tails of the histone proteins that can affect the expressivity of a gene’s transcript. (C) Chromatin remodeling proteins can remodel the chromatin environment by affecting how tightly and loosely packed histones are and ultimately contribute to the gene’s expression. (D) Regulatory RNAs, such as long non-coding RNAs and microRNAs, can affect alternative splicing and protein expression.