The Epigenome is a combination of many chemicals/proteins that are used to suppress or express (control) certain genes in a genome . They maintain control of the genome by the use of methylation and the particular properties of histones . Unlike the Genomic of organisms, epigenomic modification isn’t permanent allowing more adaptivity and flexibility to new environmental and lifestyle . Epigenomic modifications don't physically change the genetics of the organism but like genomics, can be passed down for many generations. Alteration of the epigenome is mainly seen in specialised cells to make them efficient in their function (this is done so by the process of deactivating/reactivating gene sequences in the genome) .
Influencers of the Epigenome
- The DNA of an organism is compacted into the cell using histones . Histone influence epigenomics by modifying the degree of expression/inhibition of a specific gene depending on the tension of the DNA around them. DNA that is wrapped tighter around the histones has a more inhibitory factor of gene expression due to the genes being unavailable to modify leaving them in a deactivated response. Genes that are loosely wrapped histones are open for modification by methylation and so are often activated and deactivated due to environmental stimuli.
- Methylation is the "switch" function of epigenomics. This is due to the methyl group joining to the histone/gene forming an epigenetic tag on it cause the total activation or deactivation of the gene . These tags bind to the promoters of some influencing an inhibitory response preventing further transcription of the gene .
- ↑ 1.0 1.1 1.2 1.3 1.4 National Human Genome Research Institute, Epigenomics, April 1st 2016, citied 16th November 2017, https://www.genome.gov/27532724/epigenomics-fact-sheet/
- ↑ 2.0 2.1 2.2 Nature Education, Epigenomics: The New Tool in Studying Complex Diseases, 2008, citied 16th November 2017, https://www.nature.com/scitable/topicpage/epigenomics-the-new-tool-in-studying-complex-694#