Epigenetics: interaction of DNA methylation and chromatin
Epigenetics is a field where advances are being made daily. Epigenetics is defined as “heritable changes in gene expression that occur without a change in DNA sequence,” as stated by Dr. Alan Wolffe. A way in which we can understand this definition is by taking the analogy of a card game. The cards, the DNA sequence, have been dealt and will not change, however we need to understand how to play the cards, the rules, which is epigenetics. The guidelines can vary and completely change the way the card game is played and who comes out on top. The rules that are studied and understood through this research paper are those of DNA methylation and chromatin. These changes can produce large variations in the gene expression of cells while maintaining the same DNA sequence.
Since all the somatic cells in our body contain the same DNA, the difference lies in the genes that are expressed. Most of the time, the majority of genes are regulated by repressing transcription, so the genetic information is used selectively. Epigenetics covers a wide field; contained in it are “DNA methyltransferases, methyl-CpG binding proteins, histone modifying, enzymes, chromatin remodeling factors, transcriptional factors and chromosomal proteins” as well as “centromere, kinetochore and telomere.” Chromatin is made of DNA packed around histone proteins and it also contains non histone proteins. The histones maintain the DNA shape and structure. This chromatin can occur in different forms. One is euchromatin, here the chromatin is not coiled so tight, but expanded so there is room for transcription factors to come in and there is a lot of actively transcribed genes. This is possible because of the exposure of the sequences when the chromatin is stretched out. Conversely there is a state in which the chromatin is packed and coiled, and there is no access to the sequence so transcription does not take place. This state is called the...
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