Thursday, June 2, 2016

Of Telomeres, Eternal Youth, and Lobsters

If you have taken AP Bio, you will know that when DNA replicates, a small piece is cut off of the end each time (see the following image to attempt to understand, they explain it far better than I could).



Now, as one can imagine, when a piece of DNA is being removed with each replication, the entire strand is going to be shortened more and more over time. DNA replicates hundreds of times in the human lifespan, and it’s pretty unhealthy to lose all that DNA, right?

That’s where telomeres come in. Telomeres are pieces of DNA that hang out on either end of the functioning strand and that do not code for anything at all in the cell’s genes. They’re essentially buffers for the DNA, as when the DNA is replicated, only the telomeres are removed.

Until time runs out. 

There are only so many telomeres — humans can have up to 15,000 base pairs (letters, if you will) in their telomeres. And DNA replication happens frequently. Sooner or later, everyone runs out. And many scientists believe this is a root cause of the human aging process.

Now meet the Lobster.
This guy doesn’t have any of our telomere problems — because he can regenerate his telomeres.

Lobsters possess a special enzyme called telomerase, which rebuilds their telomeres between divisions. This means that no matter how many times a cell divides, it’s nowhere closer to having its DNA destroyed. And the lobsters don’t get old. 

Throughout its life (which can be over 100 years!), a lobster maintains a pretty constant state. His skin (shell?) does not sag and his metabolism does not slow down. They are as youthful as ever, and scientists believe this is because of the benefits of telomerase. Lobsters will eventually die, usually because of predators, but sometimes because they just can't make shells big enough to fit in anymore, but their lives are very different because of this unusual enzyme. 

Now here's where it gets even wilder. Turns out humans have telomerase too -- in children's growth cells, and in cancer cells. Turns out the same enzyme that allows lobsters to stay young is killing millions of people. This weird pattern has generated some important questions: 

Could the lobster be the secret to eternal youth? Could it help us stop cancer?

We’re not sure yet, but these phenomena look pretty interesting nonetheless. Scientists are hoping that telomerase will help us fight cancer, improve skin graft treatment, and, of course, combat aging. Many are working with it right now, and I, personally, am very excited to see where it goes. 

If you want to find out more, check out the following: 
Dr. Joe Dispenza
Smithsonian Magazine


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