developmental biology, epigenetics refer to events that alter gene activity without directly impacting the DNA sequence. For this review, epigenetics includes DNA methylation, histone acetylation and methylation, posttranscriptional regulation of gene expression via microRNAs, and multigenerational (referring to intergenerational and/or transgenerational) effects. These events are important during development to direct cell proliferation, differentiation, and neural patterning (Guibert and Weber, 2013; Monk et al., 1987), as well as in the postnatal and adult brains, where de novo epigenetic modifications represent a path through which environmental influences can affect gene activity (Jones and Takai, 2001).
