An introduction to epigenetics

In recent times, a new area of genetics termed epigenetics has emerged. It seeks to uncover the relationship between our genes and environment. At the core of this novel field is the principle that gene expression can be altered without modifications to the DNA sequence itself. Epigenetic changes to DNA involve the addition of methyl or acetyl groups. Methyl groups decrease gene expression by making DNA more tightly bound around histones, forming heterochromatin, whereas acetyl groups do the opposite; they increase gene expression by loosening histone-bound DNA, forming euchromatin. The addition of these chemical groups to DNA is mediated by enzymes that act on signals our bodies receive from our environment such as diet, stressors, and exercise.

Epigenetic mechanisms of gene regulation have gained notoriety in the scientific community as it is suggested that these changes can be passed down to future generations through germline cells. This means that our grandparents’ diets can influence whether we develop diabetes or not. This neo-Lamarckian concept of evolution challenges the current Darwinian understanding of evolutionary genetics where phenotypic traits are believed to emerge due to genetic mutations and natural selection. Understanding epigenetic modifications opens new doors for potential clinical therapies as by modifying harmful epigenetic changes, we may be able to treat various diseases. This field also highlights the importance of a healthy lifestyle, proper nutrition, and avoiding stressors like smoking and radiation, not only for us but for future generations as well.

A noteworthy study on exercise

A study conducted by Sailani et al.1 delves into the effects of lifelong exercise on DNA methylation patterns in genes related to metabolism, skeletal muscle properties, and myogenesis. They used two groups with different levels of physical activity. Individuals from one group reported being physically active by playing various sports and engaging in other forms of activity such as cycling, hiking, running, and swimming; the other group were reported to be physically inactive but healthy.

The active group exhibited promoter hypomethylation in genes related to insulin sensitivity, muscle repair and development, and mitochondrial respiratory complexes. Compared to the inactive individuals, a significant increase in hypomethylation was seen in 714 promoters in the active group. Bearing in mind that the inactive group were healthy despite being inactive, this significant difference in methylation pattern is remarkable to see and hits home the gravity of epigenetic influence in our lives. As a result of hypomethylation, these genes would have a higher rate of expression in the active individuals. An example of one such gene is GYG2 which codes for the glycogenin 2 enzyme involved in glycogen synthesis. With enhanced glycogen synthesis we can expect to see improved physical performance and recovery in the active individuals. Along with improved skeletal muscle properties and metabolic profiles, we can assume that the active group will have a higher life expectancy and quality of life than the inactive group.

As we can see, epigenetics holds a lot of promise for the future of genetic research. By understanding the extent to which epigenetic modifications affect our lives, we can take measures to encourage positive changes to our genomes for greater health, happiness, and vitality.

Written by Malintha Hewa Batage

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