On Epigenetics

When I was in seventh grade, I learned that our genes can't be changed, ever. Once we go from gamete to fertilized egg, that's it. Stuck for life. They even mentioned some poor schmuck who thought that genetic evolution due to behaviors (i.e., changes that didn't involve actual gene mutations) could be passed onto later generations. Ha! Hahaha!

Fast forward four years. I'm in high school now, and my AP Bio teacher is telling me that yeah, we have these genes, but some of them can get turned on and off, kinda like light switches. That the genes themselves are recipes, and the ribosome is the kitchen-- but who controls which meals are created, and when?

I didn't learn the word epigenetics until college, but by the time I did, I understood exactly what it meant. Epigenetics is the concept of the chef in the cooking metaphor-- it's the factors that control gene expression. Things like histone modification and DNA methylation, markers that promote or downregulate the use of those recipes. These physical modifications that surround DNA send messages like, "hey guys, let's, like, never transcribe this POKEMON gene." (Yes, there was a cancer gene that was called POKEMON... until Nintendo threatened to sue.)

The ways in which epigenetics manifests, or has the potential to do so, are nuts. Things like grandchildren of famine survivors being more susceptible to diabetes; chemical exposure resulting in disorders that persist through generations; and maybe even sexual preference.

Epigenetics is interesting to me because it's super relevant to the interactions between the microbiota and the human immune system. Certain microbes have the ability to flip genes on and off (for better or for worse) in susceptible individuals. Sometimes this is good: many people take probiotic supplements because they promote anti-inflammatory pathways and a tolerant immune system. On the other hand, some pathogenic bugs cause inflammation and sickness, even cancer.

It also makes our diet seem that much more important, like a drug we feed ourselves constantly. I think of the many stories I've heard of autoimmunity or cancer being reversed or vastly tempered through dietary modifications*, and I am amazed. It's both heartening and terrifying to know that we have the power to influence our biological makeup, simply by adjusting our everyday habits. It puts the onus on the individual to act in her best interests: eat right for your body, sleep enough, exercise, brush your teefs. Sometimes it isn't enough, but sometimes that's all it takes. Epigenetics is the bridge connecting the duality of nature vs. nurture; it's a clear demonstration of the capability of our environment to influence our phenotype (genetic output) and those of our progeny.

Personally, I think RuPaul says it the most eloquently.

*obv this is not par for the course, but I think we can all agree that it happens and is amazing, right?