How does epigenetics work?
We are not determined by our genes. The genetic information contained in our cells is consistent, but the expression of our genes is dynamic and flexible.
Genetics and Epigenetics
A gene is a segment of the DNA molecule that corresponds to a distinct code. This code contains the information needed to make a protein.
YT Short
All of our cells have all of our genetic information. This “library” of instructions was inherited from our progenitors, it is stable and does not leave the cell nucleus.
It is necessary to transcribe the information, to make copies that are sent to the cell's machinery that translates them into proteins.
The activity of these proteins leads to the expression of certain physical features.
Despite the stability of the instructions, their expression is not fixed.
This is where information “over genetics” comes in, known as epigenetics.
Our physical traits are not just determined by the genetic codes we've inherited, there are changes in gene expression in response to environmental stimuli.
These changes are dynamic and flexible: they respond to stimuli inside and outside the cell, and they are influenced by physiology or entirely by the environment to which the organism is exposed.
3 Epigenetic Mechanisms
YT Short
Changes in gene expression are mainly controlled in three ways:
The gene with an epigenetic marker is “turned off” directly in the DNA molecule, not allowing it to be read.
This mechanism is part of the normal cellular control of gene expression.
All of our cells have the same information but the moment they have differentiated and specialized in a function, certain genes are marked as: “do not read”.
This allows us to have completely different cells carrying out very specific functions, but having exactly the same genetic information.
Epigenetic changes can happen not in the DNA code, but in the structures that help to “arrange” it - the histones.
These modifications in histones can facilitate access to information and thus allow its copying, or hinder this access, making gene expression more difficult.
The changes in histones can still be transient, helping to control the volume of gene expression, or they can become permanent, preventing future access to the information contained in that gene.
There are also epigenetic mechanisms that occur after transcription, at the time of building proteins.
Epigenetic factors may appear in greater or lesser concentrations and prevent or make it difficult to read the “copy” of the instructions for building a certain protein.
Flexibility of epigenetics
YT Short
The flexibility of the epigenome allows us, even with fixed genetic information, to adjust to changes in the world around us. It allows our body to “learn” from experience, and to be adaptable to environmental conditions.
But it also allows harmful factors to affect us and integrate into our epigenomic information, and result in negative consequences or the onset of disease.
Beware of pseudoscience
Epigenetics is a relatively recent science, there is already a lot of data but even more questions to answer.
The fascination with the possibility that we can alter the expression of our genes can lead to false conclusions or unrealistic expectations.
We must be especially wary of pseudoscience.
Be gentle with yourself,
see you soon.
Suggested reading:
