The human genome has always been
understood as the most basic code that defines who we are. Our genes are a set
of unchangeable instructions – but what if there was a way to alter how these
instructions were read? The growing field of epigenetics addresses this idea
that there can be variations in how genes are expressed.
Epigenetics is the study of
biological modifications that change how our genes are expressed without
altering the actual genetic code. At its simplest, epigenetics looks at how environmental
and behavioral factors – things like diet, exercise, and stress – influence not
only our health but also the health of our children and future generations.
Similarly, our parents’ and grandparents’ habits may have changed how the genes
they passed on to us are displayed. For
example, some epigenetic mechanisms silence or activate genes, which can lead
to certain genetic diseases.
Several studies in the last decade
have advanced our understanding of epigenetics and the potential consequences
(or benefits) of some behaviors and health indicators. In one study, mice whose
mothers spent more time licking and nursing them as babies were shown to be
less anxious than mice who did not receive maternal grooming. Upon closer
examination, this trend was shown to be linked to epigenetics. Mice who
received maternal grooming when they were young had acquired molecular level
modifications that silenced genes related to stress response. Another study
demonstrated that pregnant mice who were fed a methyl-rich diet during
pregnancy gave birth to healthier babies with darker colored fur. Mice who were
given a low-methyl diet gave birth to offspring with lighter pigmentation who
were more prone to obesity as they grew up. Again, these traits occurred
because certain genes were silenced based on the diet the pregnant mice were
fed. This study was particularly interesting because is showed that maternal
diet can have an effect on the way genes are expressed in their offspring.
Studies about epigenetics reveal
important insight into how external factors can influence our genes. Even though
we are born with a fixed genetic code, our environment and behavior may impact
the way our genes are expressed. Does this mean we can do things to actively
change our genetic "fate"? Right now, the answer is no. There is still a lot to
learn about epigenetics and how our actions effects our genetic code, as well
as gene expression in future generations. This will certainly be an interesting
field as new information unfolds!
Dolinoy, D. C. (2008). The
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Champagne, F. A. (2012). Epigenetic Influence of Stress and the Social
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Weinhold, B. (2006).
Epigenetics: The Science of Change. Environmental
Health Perspectives, 114(3),
Christoph Bock, Max Planck Institute for Informatics (Own work) [CC BY-SA 3.0(http://creativecommons.org/licenses/by-sa/3.0)], via Wikimedia Commons