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Ricky
SFN Die Hard
USA
4907 Posts |
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Valiant Dancer
Forum Goalie
USA
4826 Posts |
 Posted - 12/15/2004 : 15:15:37 [Permalink]
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quote:
Originally posted by Ricky
Didn't want to derail the other topic, so I made this one.
On http://www.xs4all.nl/~mke/Sperm%20problem.htm it says:
quote:
You see, old age is locked in your DNA. So your clone will look like a baby, but its DNA will be as old as you! So by the time you die of old age, so does your clone. It's as simple as that.
Now all DNA does is code for proteins. Now for old age to be locked in your DNA, it would have to have some kind of timing mechanism. I know red blood cell have this, but I thought they were special because they don't contain mitochondria so they don't use up any of the oxygen they store, and thus have to die after a short amount of time.
So is it true that old age is in DNA, and how exactly does it work?
I think they are referring to telomeres which is a sequence off of the DNA strand which have to do with cell replication.
http://www.infoaging.org/b-tel-home.html
So far, the research has been inconclusive and by no means link short telometers and death. |
Cthulhu/Asmodeus when you're tired of voting for the lesser of two evils
Brother Cutlass of Reasoned Discussion |
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H. Humbert
SFN Die Hard
USA
4574 Posts |
Posted - 12/15/2004 : 18:36:03 [Permalink]
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What about those samples of skin cells that keep growing and being cultured all over the world? Does that mean the person (woman, I think) who donated them never aged or died?
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"A man is his own easiest dupe, for what he wishes to be true he generally believes to be true." --Demosthenes
"The first principle is that you must not fool yourself - and you are the easiest person to fool." --Richard P. Feynman
"Face facts with dignity." --found inside a fortune cookie |
| Edited by - H. Humbert on 12/15/2004 18:36:15 |
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tomk80
SFN Regular
Netherlands
1278 Posts |
Posted - 12/16/2004 : 08:48:53 [Permalink]
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quote:
I think they are referring to telomeres which is a sequence off of the DNA strand which have to do with cell replication.
http://www.infoaging.org/b-tel-home.html
So far, the research has been inconclusive and by no means link short telometers and death.
From what I've read, the research done till now does suggest a link between short telomeres and disease/morality. What is not known however, is whether short telomeres are only a marker of lower survival or whether telomeres are actually a cause of lower survivability.
http://www.infoaging.org/b-tel-18-r-shortlink.html |
Tom
`Contrariwise,' continued Tweedledee, `if it was so, it might be; and if it were so, it would be; but as it isn't, it ain't. That's logic.'
-Through the Looking Glass by Lewis Caroll- |
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Plyss
Skeptic Friend
Netherlands
231 Posts |
Posted - 12/17/2004 : 05:21:21 [Permalink]
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quote:
Originally posted by H. Humbert
What about those samples of skin cells that keep growing and being cultured all over the world? Does that mean the person (woman, I think) who donated them never aged or died?
These cells can keep growing because they are cancerous. Such cell-lines can be artificially created by fusing healthy cells with cancer cells or by transfection with certain virusses (at least, that's what the molecular biologists tell me). The best-known example are the so-called HeLa cells. All HeLa cells are derived from Henrietta Lacks, a 31 year old woman from Baltimore, USA, who died of cervical cancer in 1951. Over 50 years later "her" cells are still being used in research. |
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Starman
SFN Regular
Sweden
1613 Posts |
Posted - 12/17/2004 : 05:39:30 [Permalink]
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quote:
Originally posted by Plyss
The best-known example are the so-called HeLa cells. All HeLa cells are derived from Henrietta Lacks, a 31 year old woman from Baltimore, USA, who died of cervical cancer in 1951. Over 50 years later "her" cells are still being used in research.
I've read somewhere that members of her family want a cut. |
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Dude
SFN Die Hard
USA
6891 Posts |
Posted - 12/18/2004 : 18:01:21 [Permalink]
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quote:
Now all DNA does is code for proteins.
DNA stores information. Out of the approximatle 3.2 billion base pairs, the human genome contains 25-30k genes. Each gene codes for a specific protien.
Not all genes are switched on in all cells.
(the processes involved in gene switching, cell signalling, ect, are a big branch of science at the moment. There is a tremendous ammount to be learned)
The vast majority of the human DNA sequence has an unknown function (if any).
Telomeres are a repeating sequence of base pairs at the end of each strand of chromatin. They are shortened with each mitotic cell division. The function is thought to preserve the informational sections of the chromatin from losing data with cell division. WHen the cell starts to lose nformation due to chromosomes shortening with cell devision, the cells no longer divide.
There is an enzyme, telomerase, that replaces the telomere segments that are lost. Some cancer cells (like the ones talked about earlier in this thread) produce an unregulated ammount of telomerase. It's suspected that this is one factor that allows them to remain living after many many more cell divisions that normal somatic cells could accomplish.
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Ignorance is preferable to error; and he is less remote from the truth who believes nothing, than he who believes what is wrong.
-- Thomas Jefferson
"god :: the last refuge of a man with no answers and no argument." - G. Carlin
Hope, n.
The handmaiden of desperation; the opiate of despair; the illegible signpost on the road to perdition. ~~ da filth |
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