Fig. 6.

Proposed model of MeCP2 genomic targeting to influence transcription. (A) During postnatal brain development the levels of MeCP2 (red) and mCH (blue) increase as neurons mature, whereas mCG (green) remains relatively stable. When DNA methylation patterns are fully developed together with higher levels of MeCP2 in the adult brain, differential binding affinity of MeCP2 for mCG (green), mCH (blue) and nonmethylated DNA (black) becomes apparent as illustrated in B. (C) In this context, MeCP2 can now bind available mCH sites to influence transcription. Thus, changes to MeCP2 levels or function, which lead to disease related phenotypes, only become apparent after the brain has fully matured.