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Epigenetics

In this day and age, a substantial percentage of the population is becoming increasingly aware of their health and wellness, especially their physical appearance. Many maintain their well-being by adhering to specific diets and exercising daily. Still, some succumb to less orthodox methods, such as plastic surgery or dietary supplements. However, despite these efforts, many people see very limited or unsatisfactory results from undertaking these methods. Be that as it may, what most people don't realize is that your genes play a significant role in your health, impacting your nutrition and the amount of physical activity your body can withstand. The way your genes work can be affected by your behaviours and your environment, so everything goes hand in hand. The study of epigenetics can describe this correlation.

Image is courtesy of Christoph Bock, Max Planck Institute for Informatics


What is Epigenetics?


As aforementioned, epigenetics is the study of how your behaviours and environment can impose changes that affect your genes' function. Epigenetic changes do not affect your DNA sequence, and, unlike genetic changes, they are also reversible. Although they cannot change your DNA sequence, they can change how your body reads it. Epigenetics looks at the extra layer of instructions that superimposes itself on top of DNA to control how genes are expressed. There is an evident relationship between epigenetic and genetic changes that need to be recognized. The expression of specific proteins is known as gene expression, which can depend on the level or the timing of their creation. That being said, while genetic changes can alter which protein is produced, epigenetic changes alter gene expression to activate or silence genes. As epigenetic changes emerge from your environmental exposures and behaviours, it is easy to see how your genes can interact with both. Stated, every cell in our body contains the same genetic code, but each cell has a different structure and function; so, the study of how other structures arise from the same gene sequence is known as epigenetics.


The Importance of Epigenetics


Epigenetics has been the object of increasing study as more evidence suggests that epigenetic mechanisms drive a wide variety of diseases, behaviours, and other positive health outcomes. Epigenetic changes are being increasingly studied concerning a wide variety of diseases, including but not limited to nearly all types of cancer, in addition to respiratory, cardiovascular, autoimmune, reproductive, and neurodegenerative disorders. Epigenetics can also help researchers understand why a pair of identical twins, who share the same genetic code, behave differently.

Image is courtesy of “What Is Epigenetics”

Epigenetic Modification


The epigenetics study examines how specific chemical tags attached to different parts of DNA, and its associated proteins can control gene activation and deactivation. These chemical changes are known as epigenetic modifications. Alteration of the underlying genetic code is not a result of this process. In contrast, it reveals which genes are turned on or off in individual cells, determining each cell's idiosyncratic character and functionality. Epigenetic modifications are heritable; however, enduring changes made to the DNA, which helps regulate how the genes are expressed, do not alter the genetic code. There are many forms of epigenetic modifications or epigenetic changes; they include DNA methylation, histone modification, and non-coding RNA.


DNA Methylation


The addition of chemical groups to DNA is known as DNA methylation. This group generally works by attaching to DNA in a specific site, where it interferes with the proteins that adhere to DNA to "read" the gene. The removal of this chemical group occurs through a process known as demethylation. Methylated genes are generally turned "off," and demethylated genes usually are turned "on."


Histone Modification


DNA coils around proteins called histones. Histones that are tightly-wrapped around DNA are inaccessible by proteins that "read" the gene. The genes wrapped around the histones are turned "off," and the genes that are not wrapped around the histones are turned "on." Chemical groups can be added or removed from histones. They are also vulnerable to change, depending on whether a gene is wrapped or unwrapped.


Non-coding RNA


DNA contains instructions for the production of coding and non-coding RNA. There is a significant difference, or relationship, between the roles of coding and non-coding RNA. Coding RNA is used to make proteins, whereas non-coding RNA works to regulate gene expression by adhering to coding RNA, breaking it down not to make proteins. Additionally, non-coding RNA can recruit proteins to forego histone modification so that genes can be switched "on" or "off."


References


Centers for Disease Control and Prevention. (2020, August 03). What is Epigenetics? Retrieved

December 02, 2020, from https://www.cdc.gov/genomics/disease/epigenetics.htm

Isles, A., & Wilkinson1, L. (2008, February 15). Retrieved December 02, 2020, from

https://academic.oup.com/bmb/article/85/1/35/291551

Marks, L. (2017, June). Epigenetics. Retrieved from

https://www.whatisbiotechnology.org/index.php/science/summary/epigenetics/

Science Direct. (2020). Epigenetic Modification. Retrieved December 02, 2020, from

https://www.sciencedirect.com/topics/biochemistry-genetics-and-molecular

biology/epigenetic-modification

Whatisepigenetics.com. (n.d.). Epigenetics: Fundamentals, History, and Examples. Retrieved

December 02, 2020, from https://www.whatisepigenetics.com/fundamentals/



Article author: Risheena Banerji

Article editors: Sherilyn Wen, Maria Giroux