Last Updated on 4 October 2020 by Ray Plumlee
Have you ever heard of epigenetics? Maybe you have, but then again, maybe you haven’t, so perhaps a little explanation is in order. We all know that our DNA controls what we are. A few changes in this DNA and we could all be chimpanzees. More than a few, and we wind up slime molds. Our DNA controls what we are, it tells our genes how to build us into the person we are. Epigenetics involves the study of how those instructions are carried out, and what can go wrong, or, possibly go right, when our genes start building us.
Our basic DNA has decided that we are human. But not all humans are identical. Some are tall, some short. Some black, some white. Some blue-eyed, some brown-eyed. It is the coding contained in our 20,000 genes that decide. So, the genes contained in our DNA provide instructions to our cells about how to process them. But what happens when some outside influence through a monkey wrench into the process and some tiny little process goes off-kilter? Our basic DNA has not been changed, but something may have been. There may be a slight altera4tion in the code, and a new cell may be produced with a slight difference. And if this difference is passed on to subsequent generations of our cells it could have consequences not only for ourselves but for future generations.
Epigenetics controls our genes. It does this through nature, as our genes follow the natural progression from fetus to fully developed human. From a single cell start, our genes decide how they will build us. Some of them are coded to become our skin, others our lungs. The process goes on and on, from the top of our head to the tips of our toes. Genes are either expressed or dormant. But nature can also affect our development. The environment can affect which genes are turned on or off, and this can have consequences. And this doesn’t stop once we are born. We have all heard the expression, “You are what you eat,” but we are also where we live, how we exercise, how we sleep, and every little thing we experience. All of these things can affect our genes, causing some chemical reactions around the genes that may cause it to turn on or off. In certain diseases such as cancer or Alzheimer’s genes can be switched to the opposite state of what is healthy. With more than 20,000 genes to be reckoned with, it may be a tall order, but what if we could reverse the damage, turn those genes back to their naturally healthy positions? If we could discover the cause of a disease or condition, and locate the damaged gene and reverse the damage, it could be possible to effect a cure. We could beat cancer, at last!
But where does all this leave us now? How close are we to finding a genetic cure for everything? Pretty far away it would seem. Science still does not understand the full implications of epigenetics. To avail ourselves of such a magic cure, we would have to know the fullest complexity of the human genome. We would also have to know just which diseases cause a change is what particular gene. Given all the permutations and combinations involved, the task is daunting, to say the least. But the future, when it finally arrives, could be bright, indeed. Remember that we all started out as a single cell, full of possibilities and promise. A single cell that would eventually evolve into every organ in the body, a stem cell. Dr. Shinya Yamanaki, a Japanese researcher, after extensive experimentation, has succeeded in turning the skin cell of a rat back into this basic structure, a stem cell, capable of producing a completely new rat. It took ten years, but he discovered a way to erase cellular memory and reverse the biological aging process. Imagine the possibilities if humans could avail themselves of a ready supply of stem cells. It could conceivably be possible to grow new organs to replace damaged ones.
One other implication connected to epigenetics is the discovery that our genes seem to have memories of their own. We can almost see this if we look at the breeding of hybrid animals. A female horse and a male donkey will produce a long-eared mule, while a male horse and a female donkey will produce a smaller, shorter-eared hinny. How is this possible if the basic contributing cells themselves, the egg and the sperm, did not contain some memory of their origin? There is even some evidence for this cellular memory in humans. In 1944 the country of Belgium suffered a severe famine due to German restrictions on the import of food. Children born to women who were pregnant at this time seem to suffer from a higher degree of adverse health conditions such as diabetes, obesity, and mental illness. This could, in fact, be attributed to the fact that they suffered from malnutrition in utero. But surprisingly, the grandchildren of this generation of famine survivors also showed the same inclinations. So, it seems possible that epigenetic changes can be inherited even if the underlying cause of the change is not experienced.
It certainly won’t come tomorrow, or probably the next day, but research indicates that, as we grow to understand the way our bodies work at the most basic cellular level, we are getting closer and closer to achieving the goal of a longer and healthier life. And by tweaking our own epigenetic changes we can improve generations to come as well.