Junk DNA and Aging

[apendrapew]

I've read that aging is due to damaged DNA in our cells among other things. So I was thinking maybe junk DNA does afterall have quite an important purpose: taking the hits for the genes that actually produce protein (forget what they're called.. exons?)

The oxidation of glucose supposedly damages our DNA in very small amounts and over time it results in the effects of old age. I've read about one experiment where control monkeys were fed a normal amount of food, whereas the monkeys being experimented on were fed 1/3 less. The ones fed less lived substantially longer. The logic: the less you eat, the lower your metabolism, the less food you break down, the lesser damage done to the DNA.

If we didn't have junk DNA, whatever it's composed of, it seems that we'd age a lot more quickly because whenever our DNA takes a hit, since the DNA wouldn't be junk, it would be DNA that's doing something important.

 

[Mrhero54]

very interesting, this is a very good theory of junk dna. perhaps this is something worth futher research.
Where did you come across that monkey study?

 

[Idle Mind]

Well, aging is supposedly due to damage to telomeric DNA, which is found at the ends of the DNA molecule. It is true, however, that the vast amounts of DNA in between genes makes it less likely for mutation to occur, but I don't think it has a direct effect on aging.

Where did you find that study? It seems suspect, since glucose metabolism is not performed in the nucleus, where the DNA is kept. Unless they mean mitochondrial DNA. I don't know, though. Do you think you could find a link?

 

[BigBlueHead]

"Junk" DNA is already being found to have other purposes - regions that do not code directly still have other effects, telomeres being a perfect example.

Each time a chromosome is copied in mitosis a little bit is lost off of the end because of the copying process. The lossy end is where the telomere is, and so the telomere shortens over succeeding cell divisions. Eventually the telomere is gone, and the divisions start to remove more important bases from the end of the chromosome.

Reduced-calorie diets have also been studied in rats, I believe. The effects may have to do with the reproductive system; several animals have been shown to live significantly longer when they were prevented from reproducing, and the reproductive system can shut down when little food is available.

 

[ElectricFetus]

Telomeric DNA like most "junk" DNA in a eukaryotic chromosome is of structural role: it is there so that the ends of the chromosome won't were down and rip up functional genes. Telomerase and telomere lyseation is control by cells to time cell and tissue development and to activate senescence(cell aging or basically cell “senility”)

So aging is not just a function of damage to cell structures (usually DNA) but is programmed into us, why? Because evolution does not evolve creature that live forever, naturally things get kill of by predators or infectious disease if these creature reproduce before hand then evolution is happy. If these creatures have genes that cause aging or lack mechanism for infinite existence evolution does not care because the creatures already reproduced.

 

[apendrapew]

Originally posted by Mrhero54
very interesting, this is a very good theory of junk dna. perhaps this is something worth futher research.
Where did you come across that monkey study?

I think I read it in Parade a few years ago.

 

[apendrapew]

A good analogy to what it would be like to have no junk DNA would be one involving data compression. Compress a data file with a really high compression scheme like [Win]Ace. I know in my experience, highly compressed files like that are a lot more volatile, meaning they're easily corrupt due to things that we take for granted ie, hard drive jitter, CRC errors, etc. If the file has been copied to a different medium a lot or been transferred somewhere else (often the case when files are compressed) that increases the chance of further "mutation". Then you extract the file and a part of it is corrupt. Happens all the time. I love analogies.