Epigenetics encompasses the modifications to DNA that influence gene expression without altering the underlying DNA sequence, and these changes can be inherited across generations.

Specifically, epigenetics involves changes in how genes are expressed, which are mediated by modifications to the DNA molecule itself or the proteins that interact with it. Common forms of these modifications include the addition or removal of chemical groups, such as methyl ($CH_3$) or acetyl ($C_2H_3O$) groups. These alterations can impact the tightness of DNA packaging, thereby affecting the accessibility of the DNA to the cellular machinery responsible for reading and transcribing genes.

Various factors can influence epigenetic modifications, including environmental exposures, dietary habits, and psychological stress. Notably, these modifications can be passed down from one generation to the next, although the mechanisms behind this inheritance are still under investigation. One potential pathway for this transmission is through germ cells—i.e., the cells that develop into eggs and sperm—which can carry epigenetic changes to the fertilized egg, leading to the formation of an embryo.

The consequences of epigenetic modifications on gene expression can be significant, contributing to the onset and progression of a diverse array of diseases, such as cancer, diabetes, and neurological disorders. Therefore, understanding the intricate mechanisms of epigenetic regulation is a critical area of research, with meaningful implications for both disease prevention and treatment strategies.