Epigenetics – an emerging area of gene research

In biology, and specifically genetics, epigenetics is the study of changes in gene expression caused by mechanisms other than changes in the underlying  DNA sequence – hence the name epi- (Greek: ???– over, above, outer) -genetics. Examples of such changes might be DNA methylation or histone deacetylation, both of which serve to suppress gene expression without altering the sequence of the silenced genes. {{{0}}}

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.

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, blood vessels etc. as it continues to divide. It does so by activating some genes while inhibiting others through the epigenetic process.

Currently, what have been well research and documentation are 2 known mediating processes – methylation and histone deacytylation. These processes could be activated by a number of environmental stimuli, in utero and childhood development, aging, diet and drugs.


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