You only have a few more genes than a lowly Nematode worm!
Fun fact: Before the Human Genome Project, expert scientists expected humans to have 125,000 genes. In actual fact, we have 25,500, which is only 1500 more than a lowly nematode worm.
Epigenetics, as a simplified definition, is the study of molecular mechanisms by which ‘environment’ controls gene activity. What does that mean? Well, if you are new to this whole thing, we first need a quick crash course in biochemistry and genetics:
- Cells are fundamental working units of every human being. All the instructions required to direct their activities are contained within the chemical deoxyribonucleic acid, also known as DNA.
- DNA from humans is made up of approximately 3 billion nucleotide bases. There are four fundamental types of bases that comprise DNA – adenine, cytosine, guanine, and thymine, commonly abbreviated as A, C, G, and T, respectively.
- The sequence, or the order, of the bases is what determines our life instructions. Interestingly enough, our DNA sequence is mostly similar to that of a chimpanzee. Only a fraction of distinctively different sequences makes us human.
- Within the 3 billion bases, there are about 25,500 genes. Genes are specific sequences of bases that provide instructions on how to make important proteins – complex molecules that trigger various biological actions to carry out life functions.
- Fun fact: Before the Human Genome Project, expert scientists expected humans to have 125,000 genes. In actual fact, we have 25,500, which is only 1500 more than a lowly nematode worm.
Now that you understand genetics, let’s learn about epigenetics. Epigenetics, essentially, affects how genes are read by cells, and subsequently how they produce proteins.
Here are a few important points about epigenetics:
Epigenetics Controls Genes. Certain circumstances in life can cause genes to be silenced or expressed over time. In other words, they can be turned off (becoming dormant) or turned on (becoming active). For decades, the biological and medical dogma written in stone was the Primacy of DNA. That is, DNA acted on RNA, which in turn acted on proteins in a one way flow of information. To suggest anything else was heresy.
We now know that it is the Primacy of the Environment that is the real case. Environmental signals act on regulatory proteins that direct the activity of Genes which then act on RNA and Proteins in a two way feedback loop.
Epigenetics Is Everywhere. What you eat, where you live, who you interact with, when you sleep, how you exercise, even aging – all of these can eventually cause chemical modifications around the genes that will turn those genes on or off over time.
Epigenetics Makes Us Unique. Even though we are all human, why do some of us have blonde hair or darker skin? Why are some of us more sociable than others? The different combinations of genes that are turned on or off is what makes each one of us unique. Furthermore, there have been indications that some epigenetic changes can be inherited. Recent studies on mice found that epigenetic factors in one generation altered gene expression in the following 14 generations. A human study in Finland found that traumatic environmental factors in one generation altered gene expression in the next generation.
If we know that certain environmental triggers affect particular genes in an adverse manner, we have the choice to avoid those triggers and reduce the chance that the gene is activated. So in some cases it is possible to have a genetic predisposition or susceptibility, but not develop the full blown genetic condition by avoiding or reducing the environmental triggers.
If we know that certain environmental triggers affect particular genes in an adverse manner, we have the choice to avoid those triggers. So remember, you are not a slave to your Genes!
If you want to delve into this further, a very readable and short book is the Biology of Belief by Bruce Lipton, who practically invented the science of Epigenetics.