What do you own that is 600 million years old? Your old suit? That little league baseball glove? Your cologne? In fact, every man possesses something that old, and believe it or not, it’s a gene. Not the clothing kind, but the kind you keep in your genome, in your chromosomes. We’ve talked about the Y chromosome in this space but lets take a moment to focus on a single tiny gene.
Tucked away in every cell of your body is a gene called Boule, a piece of DNA critical for sperm production. A colleague of mine just announced that the Boule gene is present in every organism from insects like fruit flies, to sea urchins, roosters, fish and man. It is in invertebrates and vertebrates alike. That is, this tiny bit of DNA has remained essential for making sperm through 600 million years of evolution. Surely the oldest treasure you own.
But what’s really impressive about the Boule gene is that is has not changed over time. And change is the rule with every other known gene involved with reproduction in every species. In fact, evolution of reproductive traits is how a species diverges from other species. It gives each species its identity. And this change can be very rapid: in some fish, reproductive traits are observed to change in fewer than a dozen generations. So why would this one gene stay the same?
We think that the Boule gene has remained true over 600 million years because it is essential for reproduction. Boule is a “quality control” gene that ensures all goes well as sperm are made. Just as you would want your new car to be well inspected so it is safe to drive when you buy it, you want your sperm to be reproductively fit. In fact, if the Boule gene is removed, sperm production stops entirely. Not a single sperm is made in its absence. Now that’s control.
What’s also impressive about the Boule gene is that since it is linked to sperm production, it means that sperm are very, very ancient cells. Seems that nature sticks with what is tried and true and feels no need to experiment with magic potions or fairy dust to get the job done. Reminds me of what Einstein once said while reflecting on relativity and physics: “God does not play dice.” When it comes to reproduction, the Boule gene phenomenon suggests that he may take even fewer chances.