“My DNA is running out”

Contrary to popular belief, music and science are a match made in heaven. Advertisers know that cheesy viral music videos are the best way to target a scientific demographic. And don’t rule out scientists themselves! There are a lot of nerdy and talented composers and singers out there.

Unfortunately, more traditional musicians don’t seem to care much for physics or chemistry, let alone molecular biology. Until I came across a wonderful song by Darwin Deez, that is (if you know some other cool examples, let me know in the comments). I’ve transcribed the lyrics for your convenience below!

This is golden! This is a songwriter who understands that science is poetry. “You don’t care, or understand, how it feels to be a single double strand”, that’s one of the best lines I heard in a long time. But could there be some actual science hidden beneath the lyrics? Time to find out!

“My DNA is running out”
That certainly doesn’t sound healthy.. Could it be possible that your DNA simply ‘runs out’ at some point?

Normally, no. Your chromosomes have special protection in place to prevent this from happening: the telomeres. You can think of telomeres as those little pieces of metal at the end of your shoelaces, preventing the chromosomes from unraveling. Telomeres are expendable stretches of repetitive DNA, so it doesn’t matter much if they get damaged. A special enzyme called telomerase can lengthen telomeres, making sure that the protection remains in place

Nature had them first.

So why are these telomeres and telomerases so important? During cell duplication, the DNA copying enzymes cannot continue all the way to the end of a chromosome (because there’s no 3′ OH for them to latch on to, see video below). If the DNA  wouldn’t be replaced, the chromosome would get progressively shorter after each round of cell division. This is what happens in mice that lack the telomerase enzyme. They age a lot quicker than their normal siblings, because their own chromosomes are degenerating every hour. If Darwin Deez is really losing DNA, a defective or missing telomerase might be the cause. In any case, it’s not good news for Deez’ life expectancy!

“I already lost the gene for feeling pain”
A gene exists (SCN9A) that when damaged or lost, causes it carriers to become insensitive to pain. That might sound like every superhero’s dream, but it really isn’t. Feeling pain is your body’s way of telling you that there’s something wrong, and you should pull your hand away from that dog that’s gnawing at your fingers! People with mutations in the SCNA9 gene have to learn to ‘recognize’ danger by cognition alone, which is not an easy task, especially for young children.

The Nav1.7 sodium channel, the gene product of SCNA9, with known mutations in pain disorders. Picture from second reference.

The SCNA9 gene codes for a sodium channel that causes neurons of the involuntary nervous system to fire when stimulated. Interestingly, some mutations in SCNA9 actually cause excessive channel activity, leading to periodical sensations of burning pain. Scientists have much interest in a gene like this. If they could somehow target this protein, they might be able to find another way to anesthetize patients. In any case, you’re really better of with a good-old fashioned, pain-responsive wild-type SCNA9 in any case.

Additionally and unfortunately for Darwin Deez, a loss of SCNA9 doesn’t prevent you from feeling emotional distress, which might be a bigger issue for our tormented singer..

So, before I end this paragraph, let me say that the existence of “gene X for trait Y” is a lie. SCNA9 is not ‘the gene for pain’. That’s not how genetics works. Single traits cannot be mapped to single genes, even though the job of a lot of geneticists would get simpler if it were possible. If you want to read more on this, I reccomend you read the excellent assay on MAOA, “the warrior gene” by Ed Yong.

“I’m down to six or seven chromosomes”
This is bad. Different species have different numbers of  chromosomes, sure. In fact, we humans appear to have one pair of chromosomes less than our cousins, the great apes. In our human ancestors, chromosomes 2A and 2B apparently fused into what we now call chromosome 2. That’s a whole different league than losing 40 (or 39) chromosomes though! Since most chromosomal aneuploidies are lethal, it’s safe to assume that Darwin has a big problem here..

With all these abnormalities, we can conclude that Darwin Deez makes an interesting genetic case. After the word gets out, I’m sure a lot of geneticists want to take a look at mr Deez!

As promised, the lyrics follow below:

My DNA
Is running out
I’m not the
Guy who makes you smile now
And when we talk
It’s not the same
But I’ve already lost the gene for feeling pain

So I won’t cry
No I will just pretend
I’m still the one
And that we’re in love again

When I call
You’re never home
I’m down to
Six or seven chromosomes
But you don’t care
Or understand
How it feels to be a single double strand

But I won’t cry
No I will just pretend
I’m still the one
And that we’re in love again

All these molecules don’t make me who I am
Oh, so I will just pretend
I’m still the one
And that we’re in love again

But I won’t cry
No I will just pretend
That I’m still the one I was
And that we’re in love again

Well I won’t cry, oh no!
I will just pretend
That I’m still the one
And that we’re in love again

A Short History of the Oldest Tree on Earth
Guest post: Don’t judge a cell by its coat
Unpopular Genes