Can we influence our genes?
The idea that genes influence our physique, intelligence and personality is well-established. It is common for family members to comment “He has his father’s hot-temper” or “She gets her smarts from her mother”. Recently a new concept has arisen – that of epigenetics.
Epigenetics refers to heritable changes in gene expression, without any changes in gene structure. That is, a change in phenotype without a change in genotype. It basically means that our actions or environmental influences can switch certain genes “on or off,” thus altering the results of gene expression. The molecular mechanisms underlying this are complex; they include DNA Methylation, Histone Modification and ncRNA interactions.
Let me make this clearer with the help of some examples. In one study, researchers found that fathers with a normal BMI (Body Mass Index) prior to their child’s conception, had children with a normal level of DNA Methylation (represents gene activity) on genes for Insulin type Growth Factor 2 (IGF-2). IGF-2 is a growth hormone essential for normal growth and development. The results showed how a father’s healthy lifestyle could potentially encourage a child’s healthy development down the road.
Surprisingly, such epigenetic changes can affect behavior as well. In another study, researchers conditioned mice to fear the smell of acetophenone (which is similar to strawberry or almond scent). They found that the children of the experimental group (F1 generation) were inherently fearful of the scent, despite never having been exposed to it. Same was observed with the third generation offspring of the experimental group (F2 generation).
Researchers further found that the sperm of experimental mice had altered DNA Methylation marks for the gene that senses acetophenone (Olfr-151). It may be that the traumatic exposure of the experimental mice to the acetophenone caused them to develop increased sensitivity to the smell by altering Olfr-151 gene expression. Such a change may have been passed onto their offspring.
These epigenetic changes have been observed in humans as well. In one study, pregnant mothers were exposed to a rich and learning environment which increased their Long Term Potentiation (LTP – ability to form neuronal connections, necessary for learning and storing memories). Such mothers were more likely to have children with an enhanced LTP.
Researchers believe that the mother’s learning activates an otherwise latent signaling cascade (latent Camp/p-38) that causes enhancement of the child’s LTP.
All these researches suggest something unique and empowering; our actions, habits and life experiences could actively shape the lives of our next generation. Perhaps such a realization will prompt us to live more healthy, calm and productive lives; so we can ensure the same of our children.
About the Author: Mustafa Shah is a student of medicine at Dow Medical College, Pakistan.