Methylation, imprinting and the selfish gene
Guiomar Pérez de Nanclares, Intza Garin & Elena Beristain
Living beings adapt to the environment for survival. This adaptation can be accomplished through changes in their genetic material (DNA) or by changing in mechanisms controlling the specific DNA regions that should be (in)active in an specific cell in a concrete moment (epigenetic changes). Epigenetic changes alter gene expression without changing the letters of the DNA alphabet (A-T-C-G), providing cells with an additional tool to fine-tune how genes control the cellular machinery.
In this chapter we will focus on epigenetic modifications and the theories that explain how intrauterine conditions can affect the quality of life of the descendants in their adult life. We will describe the role of methylation as the primordial mechanism for tissue specialization; the imprinting or parental-specific silencing of several genes and its effect on several (epi)genetic diseases; and finally it will be described how methylation influences short-term adaptation and the effects of environment on the methylation status and its transgenerational consequences.