What is epigenetics?

Epigenetics is the study of changes that do not involve alterations in the DNA sequence. Epigenetic changes are modifications to DNA that regulate whether genes are turned on or off. These modifications are attached to DNA and do not change the sequence of DNA building blocks. Within the complete set of DNA in a cell (genome), all of the modifications that regulate the activity (expression) of the genes is known as the epigenome. Epigenetics most often involves changes that affect gene activity and expression, but the term can also be used to describe any heritable phenotypic change. 

DNA

Epigenetics in bacteria

Epigenetics have fundamentals importance in eukaryotes, especially metazoan. Eukaryotes use epigenetics mechanism to regulate gene expressions which bacteria rarely do. In Alphaproteobacteria, methylation of adenine regulates the cell cycle and couple gene transcription to DNA replication. 

Medicines

Epigenetics has many and varied potential medical applications. It has the potential to explain mechanisms of aging, human development, and the origins of cancer, heart disease, mental illness, as well as several other conditions. The use of beta-lactam antibiotics can alter glutamate receptor activity and the action of cyclosporine on multiple transcription factors. Additionally, lithium can impact autophagy of aberrant proteins, and opioid drugs via chronic use can increase the expression of genes associated with addictive phenotypes. 

Pseudoscience

Due to epigenetics being in the early stages of development as a science and the sensationalism surrounding it in the public media, David Gorski and geneticist Adam Rutherford advised caution against proliferation of false and pseudoscientific conclusions by new age authors who make unfounded suggestions that a person's genes and health can be manipulated by mind control. Misuse of the scientific term by quack authors has produced misinformation among the general public.