Epigenetics 1983 – The Relationship Between Environmental Factors and Genes

Just as a pianist interprets the notes in a musical score and controls volume and tempo, epigenetics affects how genetic DNA sequences are interpreted in cells. Epigenetics generally refers to the study of inherited traits that do not involve changes to the underlying DNA sequences in cells.

One way DNA expression can be controlled is by adding a methyl group (a carbon atom with three hydrogen atoms attached) to one of the DNA bases, making that region of “marked” DNA less active and potentially suppressing the production of a particular protein. Gene expression can also be altered by histone proteins that bind to the DNA molecule. 

In the 1980s, the Swedish researcher Lars Olov Bygren discovered in Norrbotten that boys who went from normal eating to overeating within a single season had sons and grandsons with much shorter lifespans:

• According to one hypothesis, inherited epigenetic factors played a role. 
• Other studies suggest that environmental factors such as stress, diet, smoking and prenatal nutrition leave marks on our genes that pass down through generations. 

According to this argument, the air your grandparents breathed and the food they ate could affect your health decades later. 

In 1983, the American medical researchers Bert Vogelstein and Andrew P. Feinberg documented the first example of a human disease involving an epigenetic mechanism. Specifically, they observed a widespread loss of DNA methylation in colorectal cancers. Because methylated genes are typically switched off, this loss of methylation can lead to abnormal gene activation in cancer. Excessive methylation can also disrupt the work of protective tumor-suppressor genes. Today, drugs are being developed that affect epigenetic markers to silence bad genes and activate good ones. 

The general concept of epigenetics is not new. After all, a brain cell and a liver cell have the same DNA sequence, but different genes are activated through epigenetics. Epigenetics may also explain why one twin develops asthma or bipolar disorder while the other remains healthy.

Historical Figure Mentioned in the Article: Bert Vogelstein (b. 1949)

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