What is the science behind epigenetics? Click here to learn more about epigenetic inheritance!
Figure 1: DNA
Background
Epigenetics is the study of how behaviors and environments influence the expression of genes (phenotype) and more specifically how they work (CDC). Epigenetics does not change the expression of genes but does impact development. Currently, scientists are investigating the factors that affect gene activity. Your gene expression is the frequency at which proteins are formed by instructions from your genes (CDC). Epigenetics works to cause changes in which genes are expressed by turning gene sequences on and off. The theory of epigenetic inheritance is relatively similar to the basics of epigenetics, though it’s affected less by your own behavior and more by your experience in the womb. Epigenetic inheritance is the inheritance of certain genetic sequences passed down paternally (Lacal and Ventura). In this case, the inheritance occurs during fetal development in utero.
How Does it Work?
How exactly does epigenetics inheritance happen? For this type of inheritance to occur, it must first be identified within an egg or sperm cell. Usually, when this happens the epigenetic tags within the cells are erased during fertilization. This erasure results from a process called reprogramming which allows the fertilized egg to "start anew" and develop its own genetic code (Rettner). Epigenetic inheritance introduces the idea that the genetic information from the parent cells (sperm and egg) have somehow avoided reprogramming to be inherited by future generations (Rettner).
Epigenetics and Disease
A prominent factor in the modification of cells through epigenetics is DNA Methylation. DNA methylation is a chemical process that regulates gene expression by adding a methyl group to a DNA sequence (Simmons). The addition of a methyl group alters the structure and appearance of DNA, which in turn changes how the sequence is read by the cell's nucleus. “Although epigenetic changes do not alter the sequence of DNA, they can cause mutations” (Simmons). These mutations often lead to heritable diseases such as cancer. Cancer cells with epigenetic influence are usually identified by a low amount of DNA methylation (Emory Winship Cancer Institute). Cancer was the first epigenetically linked human disease discovered in 1983 (Simmons). Cancer can result from epigenetic changes in certain oncogenes (genes that can develope into tumor cells) as well as tumor suppressors genes (Emory Winship Cancer Institute). During mitosis, these altered cells divide and spread to eventually metastasize and spread cancer throughout the body.
Resources
CDC. “What is Epigenetics? | CDC.” Centers for Disease Control and Prevention, Center For Disease Control, 2022, https://www.cdc.gov/genomics/disease/epigenetics.htm#ref1. Accessed 27 August 2022.
Emory Winship Cancer Institute. “Cancer Epigenetics.” CancerQuest, https://www.cancerquest.org/cancer-biology/cancer-epigenetics#toc-epigenet ic-6C5a-mU4. Accessed 18 September 2022.
Lacal, Irene, and Rossella Ventura. “Epigenetic Inheritance: Concepts, Mechanisms and Perspectives - PMC.” NCBI, 28 September 2018, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6172332/. Accessed 27 August 2022.
Rettner, Rachael. “Epigenetics: Definition & Examples.” Live Science, 24 June 2013, https://www.livescience.com/37703-epigenetics.html. Accessed 27 August 2022.
Simmons, Danielle. “Epigenetic Influences and Disease.” Genes And Disease, 2008, https://www.nature.com/scitable/topicpage/epigenetic-influences-and-diseas e-895/. Accessed 18 September 2022.
Comments