Epigenetics

In biology, and specifically genetics, epigenetics is the study of heritable changes in gene expression or cellular phenotype caused by mechanisms other than changes in the underlying DNA sequence – hence the name epi- (Greek: επί- over, above, outer) -genetics. It refers to functionally relevant modifications to the genome that do not involve a change in the nucleotide sequence. Examples of such modifications are DNA methylation and histone modification, both of which serve to regulate gene expression without altering the underlying DNA sequence. These changes may remain through cell divisions for the remainder of the cell's life and may also last for multiple generations. However, there is no change in the underlying DNA sequence of the organism; instead, non-genetic factors cause the organism's genes to behave (or "express themselves") differently. There are objections to the use of the term epigenetic to describe chemical modification of histone since it remains unknown whether or not these modifications are heritable.

One example of epigenetic changes in eukaryotic biology is the process of cellular differentiation. During morphogenesis, totipotent stem cells become the various pluripotent cell lines of the embryo, which in turn become fully differentiated cells. In other words, a single fertilized egg cell – the zygote – changes into the many cell types including neurons, muscle cells, epithelium, endothelium of blood vessels, etc. as it continues to divide. It does so by activating some genes while inhibiting others.

In 2011, it was demonstrated that the methylation of mRNA has a critical role in human energy homeostasis. The obesity associated FTO gene is shown to be able to demethylate N6-methyladenosine in RNA. This opened the related field of RNA epigenetics.

Read more about Epigenetics:  Etymology and Definitions, Molecular Basis of Epigenetics, Mechanisms, Epigenetics in Microorganisms

Other articles related to "epigenetics, epigenetic":

Epigenetics in Microorganisms
... postreplicative DNA methylation for the epigenetic control of DNA-protein interactions ... make use of DNA adenine methylation (rather than DNA cytosine methylation) as an epigenetic signal ... This is an example of epigenetic regulation enabling unicellular organisms to respond rapidly to environmental stress ...
Secreted Frizzled-related Protein 1 - Epigenetics - Mechanism of Down Regulation
... This indicates that T47D cells are tightly regulated by two layers of epigenetic control (DNA methylation and histion deacetylation) and relieving inhibition by both mechanisms is necessary for reactivation ... This study shows that both the epigenetic mechanisms, DNA methylation and histone deacetylation, are involved in silencing of SFRP1 ...
Computational Epigenetics
... Computational epigenetics uses bioinformatic methods to complement experimental research in epigenetics ... explosion of epigenome datasets, computational methods play an increasing role in all areas of epigenetic research ...
Computational Epigenetics - Emerging Topics
... The first wave of research in the field of computational epigenetics was driven by rapid progress of experimental methods for data generation, which required adequate computational methods for data ... topics will continue to be major areas of research and the mere quantity of epigenetic data arising from epigenome projects poses a significant ... Epigenetic regulatory circuitry Reverse engineering the regulatory networks that read, write and execute epigenetic codes ...
Computational Epigenetics - Sources and Further Reading
... The original version of this article was based on a review paper on computational epigenetics that appeared in the January 2008 issue of the Bioinformatics journal Bock, C ... (2008) Computational epigenetics ... Additional data has been updated and added, based on a review paper on computational epigenetics that appeared in the January 2010 issue of the Bioinformation journal Lim S.J ...