Molecular Basis of Epigenetics
Epigenetics refers to changes in a chromosome which has influence on gene activity and expression. It is also used to describe any heritable phenotypic change that doesn't derive from a modification of the chromosome such as prions. Epigenetics is the mechanism for storing and perpetuating or continuing indefinitely a “memory” at the cellular level. The basic molecular epigenetic mechanisms that are widely studied at present – regulation of chromatin structure of cell through histone post-translational modifications and covalent modification of DNA principally through the method of DNA methylation. Chromatin is a dynamic structure that integrates potentially hundreds of signals from the cell surface and has effects of coordinated and appropriate transcriptional response in cell. It is increasingly clear that epigenetic marking of chromatin and DNA itself is an important component of the cell signal integration of entire function that is performed by the genome. Moreover, the changes in the epigenetic state of chromatin in cell can have lasting effects on behavioral changes.