Epigenetics studies genetic effects notencoded in the DNA sequence of an organism, hence the prefix epi- (Greek: επί– over, outside of, around). Such effects on cellular and physiological phenotypic traits may result from external or environmental factors that switch genes on and off and affect how cells express genes. These alterations may or may not be heritable, although the use of the term epigenetic to describe processes that are heritable is controversial.
The term also refers to the changes themselves: functionally relevant changes to the genome that do not involve a change in the nucleotide sequence. Examples of mechanisms that produce such changes are DNA methylationand histone modification, each of which alters how genes are expressed without altering the underlying DNA sequence. Gene expression can be controlled through the action of repressor proteins that attach to silencer regions of the DNA. These epigenetic changes may last through cell divisions for the duration of the cell’s life, and may also last for multiple generations even though they do not involve changes in the underlying DNA sequence of the organism; instead, non-genetic factors cause the organism’s genes to behave (or “express themselves”) differently.
Connie’s skin tips: Sleep, hydrate, moisturize, use Vit C serum (DIY), wash with lemon and left over tea bags and apply sunscreen (from whole foods store).