A blueprint is not a house. I’ve noticed a lot of news lately about the discovery of the gene that controls something or other. For example, last Friday the San Francisco Chronicle carried a New York Times article with the title “Study pinpoints gene controlling fear: Discovery could help humans with disabling anxiety.”
The human genome is like a blueprint. The promise implied by the headlines and accompanying articles is that knowing what lurks behind our genetic closet doors will empower us to promote what’s good and prevent what’s bad.
Let’s step back a moment and remember how genes work. DNA makes up our genes, stored in each cell’s nucleus and mitochondria. A chemical signal causes a segment of DNA to unwind. Using the chemical bits that make up the DNA segment as a pattern, a protein is built. The protein launches a whole biochemical process that can have a long chemical path with many biological effects. The chemical signal that starts it all can also be at the end of a long biochemical path. What distinguishes one tissue—that is, one cell type—from another is whether a segment unwinds in response to a signal. The genes of your liver cells unwind to chemical signals that your brain cell genes do not.
This is a roundabout way of saying that genes express themselves in response to their environment, that the path from the environment to the gene and back out to the environment is not a simple one, and that genes in specific tissues respond according to what they’re built to do. The 22,000 genes identified by the Human Genome Project was a lot less than what they expected to find. It turns out that, genomically speaking, we’re virtually indistinguishable from chimpanzees.
On the other hand, we have something like 400,000 unique proteins. Or at least that’s the current estimate. Many of our most profound biological responses to our environment are built from this nexus of proteins, not from our DNA. In the last decade, the concept of proteomics has gained currency: the study of that vast protein nexus as the engine of our biology, a field parallel to but vastly more complex than genomics.
So does pinpointing the gene that causes fear help us live a better life?
Another piece of research that showed up in the news last week concerned how nutrients can permanently alter how genes respond to a signal. The experiment was on mice. Mice that are nurtured are less prone to stress (and its health consequences) than mice that aren’t nurtured. The researchers discovered the gene that was expressed by nurturing. Using a nutrient, they were able to turn off that gene and turn well-adjusted mice into stressed-out mice.
Did we need to know that someone who is nurtured will be less prone to stress than someone who is not?
I’m not downplaying these discoveries in the least. They’re extremely important. But these are discoveries along the way to better understanding how to support our health and well-being. They are not occassions for gah-gah over the control we think we have over our biology because we have looked at the blueprints and know where the closet door for fear or stress is located.
From a blueprint, you can build a house of horrors or a palace of delight. Not only are your genes not your destiny, they’re not even most of who and what you are. That depends on what you and we together have built.
The issues in this article are developed (with references) in issue #9 of the Progressive Health Observer in a review article titled “Epigenetics and Proteomics.”