Divide and Conquer on a Cellular Level
I am an unabashed science geek so biology, particularly human biology, has always been a particular fascination of mine. It may sound naive, but I’m amazed by how the body incorporates so many diverse and intricate systems to form “us.” Needless to say, when news of the first “three-donor” baby hit last week, it caught my attention.
By now, most everyone has seen the double-helix and is familiar with at least the concept of DNA; the basic roadmap of what we are as human beings as found in a cell’s nucleus. What you might not know is that there’s another, fragmentary, set of DNA found in a cell’s mitochondria. If you aren’t familiar with mitochondria, don’t worry about it. Unless you happen to be a biologist, you probably didn’t learn much about them in high school aside from the fact that they exist.
Mitochondria are structures within cells that convert the energy from the food we eat into a form of energy that cells can actually use. They play another important role, which I’ll get to in a minute. The DNA in them, known as mtDNA, is also passed down from mothers to both daughters and sons, so while DNA is the roadmap of life, mtDNA is often thought of as an extremely durable time capsule. When you see news articles about scientists sequencing the genes of ancient humans, they’re most likely working with mtDNA because it doesn’t degrade as quickly as DNA.
I don’t want to rehash sex education class for anybody, especially since it would probably raise my boss’s eyebrows, but normal human conception involves a father’s sperm fertilizing the mother’s egg. That’s why the process of in vitro fertilization is fairly straightforward, even if the process itself is rather complex. That’s what’s known as “two-donor” conception. In this case of three-donor conception, the mtDNA was removed from the mother’s egg and replaced with another donor’s, then the egg was fertilized with the father’s sperm. That egg was then carried to term and resulted in, so far at least, a normal baby.
This is where the other important role of mtDNA comes into play, which is preprogrammed cell death. A normal human cell will divide between 50 – 70 times, which is known as the Hayflick Limit. While the role of mtDNA in that process isn’t entirely understood, it is theorized that it acts as a cell’s internal clock. That’s also why we age and eventually die; we hit the point where sufficient numbers of our own healthy cells can no longer divide, so our internal systems break down and eventually cause death. That’s also part of why cancer has bedeviled us, with cancerous cells can dividing and dividing and dividing beyond the Hayflick limit, subject to no internal clock.
The transplantation of mitochondrial DNA has very real implications for biotechnology. The fact that is was successfully done, at least in the one case, means that it can likely be done again. If scientists can figure out how to do that on a larger scale – it’s estimated that there are more than 37 million cells in the human body – it is possible they could figure out how to at least slow the process of aging. If they can figure out how to do that in cancerous cells, they could essentially program them to die on their own.
Granted, it’s still years from commercialization, especially since ethical concerns prevent a lot of intensive research on the mitochondrial DNA transplantation in much of the world. But the fact that it has been done once means that it’s much more likely to come to fruition down the road. Aside from the human suffering it would relieve, can you imagine how an investment in a company that slows aging or cures cancer would pay off? And you can bet more companies will start delving into it.
That’s why the technology sector is so attractive (btw, we cover the kind of companies that stand to benefit from this type of groundbreaking research in Breakthrough Tech Profits). Not only can you make money, you can do some real good in the process.