Aging process and DNA diseases

[vincenteam2]

Hello,

 

I have a question about the aging process.

We can often read in the scientific papers that part of the aging process is due to DNA diseases.

Following this principle, I wonder why those mutations and diseases accumulated within a lifetime in the DNA molecule do not seem to be transmitted to our childs ?

 

Briefly, why do babies still born young ?

 

Are there any specific DNA repair systems within the gamet production or within the first embriologic cell divisions ?

Do DNA really degrades ?

Are there any other explanation that could explain this paradox ?

 

I thank you for your precious help.

 

Pierre.

[Dak]

Do DNA really degrades ?

 

yup. when DNA is copied, mistakes are made: in theory, these should be spotted and fixed by the cell's post-DNA-replication error-checking machinery; if they can't be fixed, the cell should be killed. however, mistakes quite often slip through, and these mistakes are sometimes in the genetic information that codes for the cell's error-checking and DNA repair mechanisms. so, you'll eventually get cells loosing the ability to check for and repair DNA damage. after that, replication errors will start to accumulate.

 

Also, DNA shortens with every replication. to overcome this, chromosomes are capped with telomeres, which are replicated slightly differently than the main body of DNA. the end result is that the telomeres shrink and enlarge with every replication. eventually, they'll become so short that they stop doing their job, and after that the chromosome will shrink with each replication, eating into the genes and causing numerouse other problems (another thing telomers do is stop chromosomes' ends being 'sticky'; so, after they're gone, the chromosomes can fuse together, which has a lot of wierd 'degradory' effects).

 

etc.

[ecoli]

Not all aging is due to DNA disease, however. There are genes that induce senescence (on purpose).

[vincenteam2]

Many thanks for your answers.

 

So if my understanding is right, the first cell of a new organism should receive brand new telomers on its chromosoms (or that chromosoms in germinal cells keep their telomers) ! Am I right ? Does germinal cells have a special treatment that keep them "younger" ?

 

I supose that post-repair DNA diseases remain very exceptional in germnal cells, otherwise most of them would lead to abortion.

 

Last question : Would you say that DNA diseases explain very little about aging process ?

 

If you find time to answer me, that would be very kind

 

Pierre.

[arnoldschwartz]

Not all aging is due to DNA disease, however. There are genes that induce senescence (on purpose).

 

On the other hand there are also genes that are known as longevity genes and these genes have been implicated in longevity.

 

From my lectures on ageing i think there is a 25% heritability componont to ageing. But that is just a ballpark figure not 100% definitive

[ecoli]

On the other hand there are also genes that are known as longevity genes and these genes have been implicated in longevity.

yeah, but the OP was regarding senescence and not longevity.

 

From my lectures on ageing i think there is a 25% heritability componont to ageing. But that is just a ballpark figure not 100% definitive

is the later percentage also a ballpark figure?

[xnebulalordx676]

Cells need plenty of antioxidants to eliminate free radicals to be able to have healthy cells. I am not sure if older cells by this same means are able to become come younger again or whether they expire and there are generated new ones that will replace those. Pomegranate beat the amount of antioxidant from vitamin E and also beat the amount of antioxidants present that are found within vitamin C. Seems pomegranates have that free radical elimination cell boosting ability most as of current findings.