Science 10 – Epigenetics

This blog post discusses epigenetic theory its origin and its how it is can be used to further the development of cancer treatments.

 – Christian Piercey, Michael Binner, Sasha Zakirov

 

Epigenetics is the study of biological mechanisms that switch genes on and off. For example, all of our cells start off as stem cells and these cells become specialized to a specific function, brain cells and skin cells have all the same genetic coding but they turn certain protein productions off when they specialize. Our environment has a big effect on our epigenetics such as our diet, sleep, exercise etc. causing chemical modifications around which genes get turned on and off. Diseases like cancer and Alzheimer’s work in the same way by interrupting or disabling the epigenetical process.

Although certain traits like our eye, skin or hair color are determined by our parents genes, the kinds of food we like and dislike are among certain traits that are epigenetic which can also be inherited indirectly from our parents but can still be changed throughout our lives. We can see this play out when looking at the foods different cultures eat in comparison to ours, something that is universally liked by another culture can taste bad to us because our ancestors were not directly exposed to it.

An epigenetic tag is used to refer to traits that become a part of us throughout our lives. Most organisms have their epigenetic tags removed from their offspring when they are being developed but occasionally certain tags don’t get removed which can cause it to pass from parent to child. Although it seems similar to a mutation it is not, mutations happen suddenly and are often very apparent but epigenetic tags are very subtle and appear over many generations. However epigenetics add a whole new level to evolution because it allows an organism to change its genetic expression to reflect their environment without ever changing its DNA makeup.

August Weismann

Now that an understanding the basics of epigenetic theory, it is important to understand its origins in order to make greater sense of how it works. Epigenetic theory has been around for a long time. In 1890, a scientist named August Weismann tested whether or not certain newly introduced traits could be inherited by future generations. He decided to amputate the tails of 5 generations of mice and managed to show that it had no affect on whether or not future generations would develop tails, he then dubbed this type of change an “environmental stimulus.” This ended up setting the bar for around half a century that genetic change is completely random.

Conrad Waddington

Then in 1956, a British biologist named Conrad Waddington published a paper in which he proved that the inheritance of a characteristic in response to environmental stimulus exists although much more subtle then Weismann had thought. Waddington tested the inheritance of the developmental plasticity that already existed within a population of mice. Mice tend to act and eat differently based on what environment they live in. (arid mice vs city mice etc.) The first generation of mice had trouble adjusting but overtime that changed and the ones who couldn’t adjust well enough had died. He made those characteristics more and more apparent by slightly changing the environment of mice over several generations. After making mice with these characteristics he bred them with other mice with the same characteristic to make it more apparent. After several generations, he realized that he could recreate these characteristics without having the mice exposed to environmental stimulus. He called this process genetic assimilation, the acquired characteristics were called “soft-inheritance,” which later evolved to be known as epigenetics.

Bradley Bernstein

Scientists have theorized for a long time that certain diseases could be cured or treated with epigenetics, the first disease to be found to relate to epigenetics was cancer. In fact, all cancer development comes from the malfunctioning of epigenetics. For example, Leukemia is caused by blood cells malfunctioning, the blood cell turns the wrong genes off causing a tumor. Recently a team of researchers at Harvard led by Bradley Bernstein tested samples of cancerous tumors revealing that even though the cancer cells came from the same patient, they were all very different. Often relapses in cancer are caused by current treatment getting grid of about 99% of the cancer cells in the patients body but for whatever reason that last one percent remains unaffected. Bernstein’s team have found that these cells tend to survive due to their epigenetical development helping them resist the treatment. We believe that this is the most important use for epigenetics because it can help us find safer and more effective ways to deal with cancer. Even today, pharmaceutical companies are developing drugs that target the epigenetic state of cells.

Overall, epigenetics is a very interesting form of biotechnology. It has a lot of potential for development and can certainly change our world for the better. Its uses in curing disease like cancer could help to better the lives of everyone affected.

 

Bibliography

“A Super Brief and Basic Explanation of Epigenetics for Total Beginners.” What Is Epigenetics?, 18 June 2019, www.whatisepigenetics.com/what-is-epigenetics/.

University , Utah. “Epigenetics & Inheritance.” Epigenetics & Inheritance, 2013, learn.genetics.utah.edu/content/epigenetics/inheritance/.

Miller, Kelli. “How Epigenetics Could Improve Your Cancer Treatment.” American Cancer Society, 22 Oct. 2015, www.cancer.org/latest-news/how-epigenetics-could-improve-your-cancer-treatment.html.

Noble, Denis. “Conrad Waddington and the Origin of Epigenetics.” Journal of Experimental Biology, The Company of Biologists Ltd, 15 Mar. 2015, jeb.biologists.org/content/218/6/816.

Images

Unknown – Edwin G. Conklin, “August Weismann” Proceedings of the American Philosophical Society, Vol. 54, No. 220. (Oct. – Dec., 1915), pp. iii-xii. 

Stoneman , Walter. Conrad Waddington. London, 8 May 1947.

Finn, Julie. Bradley Bernstein. Massachusetts General Hospital, August 2015

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