4 ms·

I have no idea what the significance of telomere is (googled it but really want a TL;DR version). Can someone explain this preliminary result in layman's terms?

by devy 10y ago

pizza 10y ago
This slide might be useful: https://image.slidesharecdn.com/telomerelength-a21stcenturybiomarkercopy-150915090850-lva1-app6891/95/telomere-length-a-21st-century-biomarker-4-638.jpg?cb=1442308214 https://image.slidesharecdn.com/telomerelength-a21stcenturyb...
dudus 10y ago
It means he didn't age as much.
- jeron 10y ago
  on top of the time disparity caused by space travel, so not only did he not experience as much time as someone on earth, he also didn't age as much?
  - trendia 10y ago
    Well I bet I can guess what Silicon Valley billionaires will be doing within a decade!
  - pizza 10y ago
    Time dilation should be negligible at low speeds; the effect is gamma = (1-(v/c))^(-.5)
    - ajnin 10y ago
      You have a small error, gamma is actually (1-v²/c²)^(-.5) , which translates to about 10ms for his 1-year stay in the ISS.
      - pizza 10y ago
        Oops, I knew that that looked too simple somehow.. thanks
  - manarth 10y ago
    The time dilation from a year on the ISS would only be around 0.014 seconds [1][2], so sadly it's not the fountain of youth just yet. [1] http://ideonexus.com/2009/02/17/how-much-does-time-dilate-for-the-iss-astronauts/ http://ideonexus.com/2009/02/17/how-much-does-time-dilate-fo... [2] https://spaceflight.nasa.gov/station/crew/exp7/luletters/lu_letter13.html https://spaceflight.nasa.gov/station/crew/exp7/luletters/lu_...
    - AnimalMuppet 10y ago
      Time dilation is never the fountain of youth. You don't experience any more time. Yes, you live to a later calendar year, but if that's at the price of having fewer seconds per calendar year in which to live, what's the point?
      - brianwawok 10y ago
        Haven't you seen Futurama? It's time travel.
nolok 10y ago
Telomeres protect your DNA from degeneration during cell division. As you age, your telomeres get shorter and shorter, and ultimately lead to cell division not producing viable cells anymore. Quoting wikipedia: > During chromosome replication, the enzymes that duplicate DNA cannot continue their duplication all the way to the end of a chromosome, so in each duplication the end of the chromosome is shortened [...] The telomeres are disposable buffers at the ends of chromosomes which are truncated during cell division; their presence protects the genes before them on the chromosome from being truncated instead. > Telomere shortening is associated with aging, mortality and aging-related diseases. In 2003, Richard Cawthon discovered that those with longer telomeres lead longer lives than those with short telomeres. However, it is not known whether short telomeres are just a sign of cellular age or actually contribute to the aging process.
- candiodari 10y ago
  To be slightly more precise and because this is a very well established mechanism that gets overridden in quite a few circumstances : this is a "death clock" built into your DNA. One of several, but rather obvious and thus well known. A number of cell functions in your body are exempt from this death clock, most obviously the reproductive cells. It causes your body to (very) slowly lose the ability to grow new cells. Also cells with shorter telomeres "senescence", which is sort of like aging : they become slower, and more brittle. Amongst the advantages this has is that it protects against cells that increase their metabolism too high and against cells that rapidly divide (by having them senescence and die). The obvious disadvantage: it eventually kills you. It seems likely, given that this mechanism is "deliberate" and definitely under the control of your DNA, that you live longer and more successfully with aging than without.
  - stormcrowsx 10y ago
    > It seems likely, given that this mechanism is "deliberate" and definitely under the control of your DNA, that you live longer and more successfully with aging than without. Not necessarily "you" but perhaps the species as a whole. Without the aging and inevitable death our ancestors may have evolved slower.
ridgeguy 10y ago
If telomere length reduction correlates with aging, then the flight twin (Scott) aged less rapidly. Not everyone agrees that telomere length is a reliable aging indicator. Another really interesting result was in DNA methylation, a gene activity regulation process [1]. Scott's DNA methylation decreased during flight while his Earthbound twin's methylation increased during that time. After Scott's return to Earth, DNA methylation in both twins returned to baseline level. The last result puzzles me. [1] https://en.wikipedia.org/wiki/DNA_methylation https://en.wikipedia.org/wiki/DNA_methylation
Symmetry 10y ago
Shorter telomeres are correlated with aging, stress, and a higher incidence of cancer. We're no entirely sure whether short telomeres can increase the chance of cancer or whether other things that can cause cancer tend to decrease telomere length or what but whichever way it goes short telomeres are a good sign in terms of health.
jcranmer 10y ago
When a cell divides, the very ends of the DNA cannot be copied. Rather than lose genetic material on every division, there is a cap of DNA at the end whose sole purpose is to be lost without ill harm when cell division occurs--this cap is the telomere. Clearly, as you age, telomeres would shrink to nothingness. However, there is a mechanism to add more DNA to telomeres... which seems to be off for most cells. So it's thought that shortening telomeres is a cause of cellular aging, and lengthening them is thought to be able to halt or reverse cellular aging and hence aging in general. The actual biology experiments generally seem to suggest more "we don't really know what's going on here." In short, what's being said is "going to space seems to show an improvement in a metric that we really, really hope is correlated with increased longevity."

I have no idea what the significance of telomere is (googled it but really want a TL;DR version). Can someone explain this preliminary result in layman's terms?

by devy 10y ago

I have no idea what the significance of telomere is (googled it but really want a TL;DR version). Can someone explain this preliminary result in layman's terms?

pizza 10y ago

This slide might be useful: https://image.slidesharecdn.com/telomerelength-a21stcenturybiomarkercopy-150915090850-lva1-app6891/95/telomere-length-a-21st-century-biomarker-4-638.jpg?cb=1442308214 https://image.slidesharecdn.com/telomerelength-a21stcenturyb...

dudus 10y ago

It means he didn't age as much.

jeron 10y ago
on top of the time disparity caused by space travel, so not only did he not experience as much time as someone on earth, he also didn't age as much?
- trendia 10y ago
  Well I bet I can guess what Silicon Valley billionaires will be doing within a decade!
- pizza 10y ago
  Time dilation should be negligible at low speeds; the effect is gamma = (1-(v/c))^(-.5)
  - ajnin 10y ago
    You have a small error, gamma is actually (1-v²/c²)^(-.5) , which translates to about 10ms for his 1-year stay in the ISS.
    - pizza 10y ago
      Oops, I knew that that looked too simple somehow.. thanks
- manarth 10y ago
  The time dilation from a year on the ISS would only be around 0.014 seconds [1][2], so sadly it's not the fountain of youth just yet. [1] http://ideonexus.com/2009/02/17/how-much-does-time-dilate-for-the-iss-astronauts/ http://ideonexus.com/2009/02/17/how-much-does-time-dilate-fo... [2] https://spaceflight.nasa.gov/station/crew/exp7/luletters/lu_letter13.html https://spaceflight.nasa.gov/station/crew/exp7/luletters/lu_...
  - AnimalMuppet 10y ago
    Time dilation is never the fountain of youth. You don't experience any more time. Yes, you live to a later calendar year, but if that's at the price of having fewer seconds per calendar year in which to live, what's the point?
    - brianwawok 10y ago
      Haven't you seen Futurama? It's time travel.

nolok 10y ago

Telomeres protect your DNA from degeneration during cell division. As you age, your telomeres get shorter and shorter, and ultimately lead to cell division not producing viable cells anymore. Quoting wikipedia: > During chromosome replication, the enzymes that duplicate DNA cannot continue their duplication all the way to the end of a chromosome, so in each duplication the end of the chromosome is shortened [...] The telomeres are disposable buffers at the ends of chromosomes which are truncated during cell division; their presence protects the genes before them on the chromosome from being truncated instead. > Telomere shortening is associated with aging, mortality and aging-related diseases. In 2003, Richard Cawthon discovered that those with longer telomeres lead longer lives than those with short telomeres. However, it is not known whether short telomeres are just a sign of cellular age or actually contribute to the aging process.

candiodari 10y ago
To be slightly more precise and because this is a very well established mechanism that gets overridden in quite a few circumstances : this is a "death clock" built into your DNA. One of several, but rather obvious and thus well known. A number of cell functions in your body are exempt from this death clock, most obviously the reproductive cells. It causes your body to (very) slowly lose the ability to grow new cells. Also cells with shorter telomeres "senescence", which is sort of like aging : they become slower, and more brittle. Amongst the advantages this has is that it protects against cells that increase their metabolism too high and against cells that rapidly divide (by having them senescence and die). The obvious disadvantage: it eventually kills you. It seems likely, given that this mechanism is "deliberate" and definitely under the control of your DNA, that you live longer and more successfully with aging than without.
- stormcrowsx 10y ago
  > It seems likely, given that this mechanism is "deliberate" and definitely under the control of your DNA, that you live longer and more successfully with aging than without. Not necessarily "you" but perhaps the species as a whole. Without the aging and inevitable death our ancestors may have evolved slower.

ridgeguy 10y ago

If telomere length reduction correlates with aging, then the flight twin (Scott) aged less rapidly. Not everyone agrees that telomere length is a reliable aging indicator. Another really interesting result was in DNA methylation, a gene activity regulation process [1]. Scott's DNA methylation decreased during flight while his Earthbound twin's methylation increased during that time. After Scott's return to Earth, DNA methylation in both twins returned to baseline level. The last result puzzles me. [1] https://en.wikipedia.org/wiki/DNA_methylation https://en.wikipedia.org/wiki/DNA_methylation

Symmetry 10y ago

Shorter telomeres are correlated with aging, stress, and a higher incidence of cancer. We're no entirely sure whether short telomeres can increase the chance of cancer or whether other things that can cause cancer tend to decrease telomere length or what but whichever way it goes short telomeres are a good sign in terms of health.

jcranmer 10y ago

When a cell divides, the very ends of the DNA cannot be copied. Rather than lose genetic material on every division, there is a cap of DNA at the end whose sole purpose is to be lost without ill harm when cell division occurs--this cap is the telomere. Clearly, as you age, telomeres would shrink to nothingness. However, there is a mechanism to add more DNA to telomeres... which seems to be off for most cells. So it's thought that shortening telomeres is a cause of cellular aging, and lengthening them is thought to be able to halt or reverse cellular aging and hence aging in general. The actual biology experiments generally seem to suggest more "we don't really know what's going on here." In short, what's being said is "going to space seems to show an improvement in a metric that we really, really hope is correlated with increased longevity."