Stem Cell Epigenetic: DNA Replication

Epigenetics refers to heritable changes in the expression of genes that are the result of factors other than an individual’s DNA sequence. Epigenetic changes can switch genes on or off and determine which proteins are transcribed. Epigenetic mechanisms involve DNA methylation (a chemical process that adds a methyl group to DNA), modification of chromatin (the complex of DNA and protein molecules that make up chromosomes) and other processes that regulate gene expression. In order for genes to be transcribed, they need to be accessed by readers of DNA; such as the enzyme RNA polymerase. By altering the physical structure of genetic material, epigenetic machinery can make certain genes inaccessible to DNA readers and therefore unreadable (i.e. turned off) or it can make them easily accessible ...