Question

Name the three key epigenetic modifications, and name a few key physiological,cellular etc. processes they are important in:

Answer 1

Epigenetics is referred to as the relation between a genome and its environment. An epigenetic modification is known as a tag. These modifications regulate the expression of genes in an organism.

The three key epigenetic modifications include,

· DNA methylation – It is the addition of methyl groups (-CH3) at CpG islands.

· Covalent modification of histone tails – Histone acetylation and deacetylation facilitate DNA protein binding leading to transcription of genes. They regulate expression of genes.

· Actions of miRNAs – miRNA are small non-coding RNAs. They are considered as negative regulators of genes by binding to multiple target sites on the complementary sequences of mRNA.

The key physiological and cellular associated with epigenetic modifications include,

Gene silencing – It is non-mutational process of inactivation. The methylation of the cytosine residues a newly synthesized daughter cell is a modification to differentiate from the parent cell.

DNA repair - Histone and DNA methylation plays a role in stabilizing the eukaryotic genomes. Epigenetic modifiers play key role in facilitating the repair of an altered DNA.