In this chapter, we focused on epigenetic modifications to the genome that regulate gene expression. Several mechanisms are involved, and epigenetic control of gene expression is important in development, cancer, and modulating the genomic response to environmental factors. From the explanations given in the chapter,

How do we know how methylation of promoters silences gene expression?

Key Concepts

Epigenetics

Epigenetics refers to the study of heritable changes in gene expression that do not involve alterations to the underlying DNA sequence. These changes can be influenced by various factors, including environmental conditions, and play a crucial role in development and disease. Understanding epigenetics is essential for grasping how genes can be turned on or off in response to different stimuli.

DNA Methylation

DNA methylation is a biochemical process involving the addition of a methyl group to the DNA molecule, typically at cytosine bases in promoter regions. This modification can inhibit the binding of transcription factors and other proteins necessary for gene expression, effectively silencing the gene. Methylation patterns can be stable and passed on during cell division, influencing cellular function and identity.

Gene Expression Regulation

Gene expression regulation encompasses the various mechanisms that control the timing and level of gene expression. This regulation is critical for normal development and cellular function, as it ensures that genes are expressed in the right cells at the right times. Epigenetic modifications, such as DNA methylation, are key players in this regulatory network, affecting how genes respond to internal and external signals.