7 ms·

Astronaut’s DNA No Longer Matches His Identical Twin’s After Year Spent in Space

176 points by Mononokay 9y ago

tyingq 9y ago
Sounds like the genesis for a new sci-fi movie.
sathackr 9y ago
I don't understand why an identical twin was needed to learn this. Couldn't an astronaut's DNA be sampled before and after a mission and compared?
- 88e282102ae2e5b 9y ago
  Sure, but everyone is accumulating mutations all the time, so you need a control on the ground to see if space itself is affecting the mutation rate.
- lithos 9y ago
  Some accounting for a year of aging. Though the news press is probably more scientifically significant.
- telchar 9y ago
  Well, consider the counterfactual of what would have happened to the astronaut's DNA if he hadn't gone to space. We don't know how it would have changed, so we can't compare it directly. Since we needed to do the experiment I'm guessing our knowledge DNA was not sufficient to predict that, so it makes sense to use a twin to get the closest proxy to the counterfactual that we can.
- mikhailt 9y ago
  How would you rule out age-related changes since this specific astronaut was in space for a year? DNA is not fixed, they change all the time. It is always better to have more data points to rule out several variables, especially considering that it is rare to have an astronaut with a twin sibling.
  - lostlogin 9y ago
    So how did it ever match his twin? Not being facetious but echoing the parent comments confusion. Do the age related changes occur the same way in identical twins?
    - mikhailt 9y ago
      This article may explain better than I can: https://arstechnica.com/science/2018/03/scott-kellys-medical-monitoring-has-spawned-some-horrific-press-coverage/ https://arstechnica.com/science/2018/03/scott-kellys-medical... > As a result, the more relevant comparison (and one NASA did) is Scott's DNA before and after his time in space. That can tell us how many changes were picked up while in space. But as noted above, he would have probably picked up some mutations even if he sat here on Earth. And that's where his twin Mark, who did sit here on Earth, comes in. Mark's before and after gives us a sense of the normal background rate of mutation on Earth. Comparing that rate to Scott's tells us the important number: the degree to which this rate is elevated in the environment of low-Earth orbit.
  - everly 9y ago
    "DNA is not fixed, they change all the time." Then why is it significant that time in space changed it?
    - tytytytytytytyt 9y ago
      It might have changed it more or in different ways.
    - mikhailt 9y ago
      It’s the rate of change compared to his twin on earth. This ars article explains better: https://arstechnica.com/science/2018/03/scott-kellys-medical-monitoring-has-spawned-some-horrific-press-coverage/ https://arstechnica.com/science/2018/03/scott-kellys-medical...
lithos 9y ago
That really clever they put the ask for notifications button over the top of the close ad button.
make3 9y ago
"Answer a question in this survey to continue reading this content" Really? no thanks
gowld 9y ago
> 93% of Scott's genetic expression returned to normal once he returned to Earth, How much was abnormal during the trip?
loufe 9y ago
The article headline is practically fake news. The article isn't very clear on it either. It's not someone's DNA that changes, that would be astounding if all the trillions of cells in your body underwent the same genetic mutations. No, this is a change in epigenetics. The things that change what parts of your DNA are expressed and are much easier to coordinate, change, and adapt in the short-term. Epigenetics are not that foreign a concept that people should assume the average reader won't understand them or will find it any less amazing.
- purple-again 9y ago
  I consider myself to be very armchair scientifically literate (zero real applied knowledge but I have consumed just about all of the pop culture created on the subject in the last 30 years). I have never heard the word epigenetics until now and am still confused about what exactly happened to this guy.
  - psergeant 9y ago
    You might enjoy reading Seveneves
    - bwb 9y ago
      Great book, another rec here too!
  - Rescis 9y ago
    Epigenetics is the idea that genes can express themselves differently based on the environment they are put in. It is how you can have the same genetic code in your brain as you skin, but the cells the genes are part of are completely different. It's how you can have a hard drive with a ton of information on it, but choose to read only small portions at a time
  - toufka 9y ago
    It has started to come up a lot recently in order to produce the above-like click-bait headlines. Here's my standard copy-pasta quoting myself from when it shows up around here: Epigenetics. It's the make-file for your genetic source code. Certain conditions can cause certain parts of your genetic code to be uncommented or commented-out within any given cell or set of cells. There are actually a number of different kinds of 'comments' (histone modifications [1]) - each set of marks are particular to a different compiler, in different contexts. And these comments/marks are copied with some fidelity to daughter-cells/children along with a high-fidelty copy of the underlying genetic code itself. So the genes (DNA) themselves are not being heritably altered, rather the recipe for which gene is produced, when, and where can be subtly changed. But again, the same mechanisms that permit the change in expression of those genes during a lifetime (of an organism, or a cell) can be subsequently changed in the next just as easily. In this way you can store the code for some trait or capability over many generations without having it always be running. It can manifest itself in individual organisms or cells as having very different phenotypes even while possessing the same underlying genetic code. [1] https://en.wikipedia.org/wiki/Histone_code https://en.wikipedia.org/wiki/Histone_code
zaroth 9y ago
Anyone else getting the “Congratulations you are a winner” ad spam / malware which takes over the page and forces a redirect? I run into this on news sites several times a week. I assume these are ads which are sneaking by the ad networks filter and running scripts on the page, just not sure how they are so damn pervasive? If these ads aren’t being paid for with stolen credit cards, then why aren’t they people buying them getting slammed with CFAA charges? Is it that hard to track these clowns down?
- namanyayg 9y ago
  Are you sure you don't have malware on your system? I haven't experienced a redirect ad in basically forever.
  - dahdum 9y ago
    It's super rare in Chrome for me, but I've seen it happen the first day on a new iPad / Safari just a few weeks ago.
- dahdum 9y ago
  I get these frequently too, especially on IOS devices. If you wipe your browser history it stops happening, so I assume they are doing some checks against Ad Network filters.
  - zaroth 9y ago
    Yes, this was on my iPhone. I always hav Safari set to Private mode so I think there is no history.
mirimir 9y ago
The article is muddled. > To better understand the genetic dynamics of each twin, Mason and his team focused on chemical changes in RNA and DNA. Whole-genome sequencing revealed that each twin has more than expected unique mutations in his genome -- in fact, hundreds. So both experienced hundreds more unique mutations? But OK, let's say that it was Scott Kelly who experienced more mutations. But which tissues did they sample? Sperm? > Preliminary results from NASA's Twins Study reveal that 7% of astronaut Scott Kelly's genes did not return to normal after his return to Earth two years ago. This is about gene expression, not necessarily mutations. And it's the key take home. Given that we've known for some decades that radiation causes mutations.
skookumchuck 9y ago
More likely aliens have replaced him with a pod person to infiltrate NASA.
gabeiscoding 9y ago
A much better source for those with an interest in the science is Chris Mason's slides from his recent talk[1] at genetics conference (AGBT) about this that he shared on twitter[2]. He's a great speaker, and a cool guy and tackles some of the most interesting (at least to hear about) science in genomics [1] https://www.dropbox.com/s/sfg6rdmgxjwdpil/Mason_NEB_talk_AGBT_2018.pdf?dl=0 https://www.dropbox.com/s/sfg6rdmgxjwdpil/Mason_NEB_talk_AGB... [2] https://twitter.com/mason_lab/status/964151387687972864 https://twitter.com/mason_lab/status/964151387687972864
gus_massa 9y ago
[I'll copy my comment from dupe story that didn't get any traction.] The article avoids all the interesting technical details. In case you are wondering if this is possible and how much of this is an exaggeration, the title of the research article is "The Landscape of DNA and RNA Methylation Before, During, and After Human Space Travel (Twins Study - Mason) - 09.27.17" https://www.nasa.gov/mission_pages/station/research/experiments/2104.html https://www.nasa.gov/mission_pages/station/research/experime... Methylation is an usual process that the cells use for enabling and disabling genes expression. It's reversible, somewhat permanent and somewhat inheritable. If you like a bad analogy, it's like making a change in the bios setup of your computer or updating the configuration of the wifi-router. It's not a firmware upgrade or a hardware modification. More info: https://en.wikipedia.org/wiki/DNA_methylation https://en.wikipedia.org/wiki/DNA_methylation
- psychobabble 9y ago
  Oh heck, me too - since I was responding to your only comment just minutes ago, here is again :) Maybe, but what is really causing the DNA methylation? The article pins it mostly on epigenetics or environment, the 'stress of space travel', including dietary constraints and oxygen levels all of which are valid. - https://theconversation.com/epigenetics-can-stress-really-change-your-genes-55898 https://theconversation.com/epigenetics-can-stress-really-ch... - http://sitn.hms.harvard.edu/flash/2017/stress-induced-dna-modification-may-play-role-mental-illness/ http://sitn.hms.harvard.edu/flash/2017/stress-induced-dna-mo... - https://www.scientificamerican.com/page/sponsored/nestle/how-diet-can-change-your-dna/ https://www.scientificamerican.com/page/sponsored/nestle/how... ooh, sponsored article, didn't catch that the first time. However, the CNN article only briefly mentions 'radiation' as a factor and likely is lumping that into the 'stressful environment' case repeated several times. Realistically, cosmic rays or radiation are far more likely to the be prevailing indicator for DNA disruption but are not plainly disclosed here. Despite much research having been done on this specific topic. Wikipedia states: https://en.wikipedia.org/wiki/Health_threat_from_cosmic_rays https://en.wikipedia.org/wiki/Health_threat_from_cosmic_rays "The potential acute and chronic health effects of space radiation, as with other ionizing radiation exposures, involve both direct damage to DNA, indirect effects due to generation of reactive oxygen species, and changes to the biochemistry of cells and tissues, which can alter gene transcription and the tissue microenvironment along with producing DNA mutations." From this paper: https://arxiv.org/abs/1406.6641 https://arxiv.org/abs/1406.6641 "In the present paper, we suggest the BNR as a cause of genetic “fails” in living cells, that is one of the possible origins of the so called spontaneous mutations. Cells exposed to the shower of electrons and ions, caused by the collision of a neutron and a proton of water, could be annihilated or experience a permanent damage, in particular, a damage in the DNA." Cosmic radiation detrimental effects to DNA confirmed by NASA in this study: https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20080029284.pdf https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/200800... And more poignantly, from https://www.vencoreweather.com/blog/2017/6/26/1200-pm-cosmic-rays-continue-to-rise-as-solar-cycle-approaches-next-minimum https://www.vencoreweather.com/blog/2017/6/26/1200-pm-cosmic... ( do not read full link if you are easily panicked ): "... there are other consequences of increasing cosmic rays according to “Spaceweather.com” including the penetration of commercial airlines, dosing passengers and flight crews enough that pilots are classified as occupational radiation workers. [Dose rates are expressed as multiples of sea level. For instance, we see that boarding a plane that flies at 25,000 feet exposes passengers to dose rates ~10x higher than sea level. At 40,000 feet, the multiplier is closer to 50x]" Sorry for the data dump, I just happened to be researching cosmic ray effects the past few evenings and have collected many interesting facts on the topic. The most I have concluded at this point is that humans, as currently derived, are not made for space travel.
tofof 9y ago
From the Nasa press release, 93% of the genetic expression pattern (very different than "DNA") remained the same before and after spaceflight, while 7% was altered. Search for "93%" in https://www.nasa.gov/feature/nasa-twins-study-investigators-to-release-integrated-paper-in-2018 https://www.nasa.gov/feature/nasa-twins-study-investigators-...

176 points by Mononokay 9y ago

Sounds like the genesis for a new sci-fi movie.

I don't understand why an identical twin was needed to learn this. Couldn't an astronaut's DNA be sampled before and after a mission and compared?

88e282102ae2e5b 9y ago
Sure, but everyone is accumulating mutations all the time, so you need a control on the ground to see if space itself is affecting the mutation rate.
lithos 9y ago
Some accounting for a year of aging. Though the news press is probably more scientifically significant.
telchar 9y ago
Well, consider the counterfactual of what would have happened to the astronaut's DNA if he hadn't gone to space. We don't know how it would have changed, so we can't compare it directly. Since we needed to do the experiment I'm guessing our knowledge DNA was not sufficient to predict that, so it makes sense to use a twin to get the closest proxy to the counterfactual that we can.
mikhailt 9y ago
How would you rule out age-related changes since this specific astronaut was in space for a year? DNA is not fixed, they change all the time. It is always better to have more data points to rule out several variables, especially considering that it is rare to have an astronaut with a twin sibling.
- lostlogin 9y ago
  So how did it ever match his twin? Not being facetious but echoing the parent comments confusion. Do the age related changes occur the same way in identical twins?
  - mikhailt 9y ago
    This article may explain better than I can: https://arstechnica.com/science/2018/03/scott-kellys-medical-monitoring-has-spawned-some-horrific-press-coverage/ https://arstechnica.com/science/2018/03/scott-kellys-medical... > As a result, the more relevant comparison (and one NASA did) is Scott's DNA before and after his time in space. That can tell us how many changes were picked up while in space. But as noted above, he would have probably picked up some mutations even if he sat here on Earth. And that's where his twin Mark, who did sit here on Earth, comes in. Mark's before and after gives us a sense of the normal background rate of mutation on Earth. Comparing that rate to Scott's tells us the important number: the degree to which this rate is elevated in the environment of low-Earth orbit.
- everly 9y ago
  "DNA is not fixed, they change all the time." Then why is it significant that time in space changed it?
  - tytytytytytytyt 9y ago
    It might have changed it more or in different ways.
  - mikhailt 9y ago
    It’s the rate of change compared to his twin on earth. This ars article explains better: https://arstechnica.com/science/2018/03/scott-kellys-medical-monitoring-has-spawned-some-horrific-press-coverage/ https://arstechnica.com/science/2018/03/scott-kellys-medical...

lithos 9y ago

That really clever they put the ask for notifications button over the top of the close ad button.

make3 9y ago

"Answer a question in this survey to continue reading this content" Really? no thanks

gowld 9y ago

> 93% of Scott's genetic expression returned to normal once he returned to Earth, How much was abnormal during the trip?

loufe 9y ago

The article headline is practically fake news. The article isn't very clear on it either. It's not someone's DNA that changes, that would be astounding if all the trillions of cells in your body underwent the same genetic mutations. No, this is a change in epigenetics. The things that change what parts of your DNA are expressed and are much easier to coordinate, change, and adapt in the short-term. Epigenetics are not that foreign a concept that people should assume the average reader won't understand them or will find it any less amazing.

purple-again 9y ago
I consider myself to be very armchair scientifically literate (zero real applied knowledge but I have consumed just about all of the pop culture created on the subject in the last 30 years). I have never heard the word epigenetics until now and am still confused about what exactly happened to this guy.
- psergeant 9y ago
  You might enjoy reading Seveneves
  - bwb 9y ago
    Great book, another rec here too!
- Rescis 9y ago
  Epigenetics is the idea that genes can express themselves differently based on the environment they are put in. It is how you can have the same genetic code in your brain as you skin, but the cells the genes are part of are completely different. It's how you can have a hard drive with a ton of information on it, but choose to read only small portions at a time
- toufka 9y ago
  It has started to come up a lot recently in order to produce the above-like click-bait headlines. Here's my standard copy-pasta quoting myself from when it shows up around here: Epigenetics. It's the make-file for your genetic source code. Certain conditions can cause certain parts of your genetic code to be uncommented or commented-out within any given cell or set of cells. There are actually a number of different kinds of 'comments' (histone modifications [1]) - each set of marks are particular to a different compiler, in different contexts. And these comments/marks are copied with some fidelity to daughter-cells/children along with a high-fidelty copy of the underlying genetic code itself. So the genes (DNA) themselves are not being heritably altered, rather the recipe for which gene is produced, when, and where can be subtly changed. But again, the same mechanisms that permit the change in expression of those genes during a lifetime (of an organism, or a cell) can be subsequently changed in the next just as easily. In this way you can store the code for some trait or capability over many generations without having it always be running. It can manifest itself in individual organisms or cells as having very different phenotypes even while possessing the same underlying genetic code. [1] https://en.wikipedia.org/wiki/Histone_code https://en.wikipedia.org/wiki/Histone_code

zaroth 9y ago

Anyone else getting the “Congratulations you are a winner” ad spam / malware which takes over the page and forces a redirect? I run into this on news sites several times a week. I assume these are ads which are sneaking by the ad networks filter and running scripts on the page, just not sure how they are so damn pervasive? If these ads aren’t being paid for with stolen credit cards, then why aren’t they people buying them getting slammed with CFAA charges? Is it that hard to track these clowns down?

namanyayg 9y ago
Are you sure you don't have malware on your system? I haven't experienced a redirect ad in basically forever.
- dahdum 9y ago
  It's super rare in Chrome for me, but I've seen it happen the first day on a new iPad / Safari just a few weeks ago.
dahdum 9y ago
I get these frequently too, especially on IOS devices. If you wipe your browser history it stops happening, so I assume they are doing some checks against Ad Network filters.
- zaroth 9y ago
  Yes, this was on my iPhone. I always hav Safari set to Private mode so I think there is no history.

mirimir 9y ago

The article is muddled. > To better understand the genetic dynamics of each twin, Mason and his team focused on chemical changes in RNA and DNA. Whole-genome sequencing revealed that each twin has more than expected unique mutations in his genome -- in fact, hundreds. So both experienced hundreds more unique mutations? But OK, let's say that it was Scott Kelly who experienced more mutations. But which tissues did they sample? Sperm? > Preliminary results from NASA's Twins Study reveal that 7% of astronaut Scott Kelly's genes did not return to normal after his return to Earth two years ago. This is about gene expression, not necessarily mutations. And it's the key take home. Given that we've known for some decades that radiation causes mutations.

skookumchuck 9y ago

More likely aliens have replaced him with a pod person to infiltrate NASA.

gabeiscoding 9y ago

A much better source for those with an interest in the science is Chris Mason's slides from his recent talk[1] at genetics conference (AGBT) about this that he shared on twitter[2]. He's a great speaker, and a cool guy and tackles some of the most interesting (at least to hear about) science in genomics [1] https://www.dropbox.com/s/sfg6rdmgxjwdpil/Mason_NEB_talk_AGBT_2018.pdf?dl=0 https://www.dropbox.com/s/sfg6rdmgxjwdpil/Mason_NEB_talk_AGB... [2] https://twitter.com/mason_lab/status/964151387687972864 https://twitter.com/mason_lab/status/964151387687972864

gus_massa 9y ago

[I'll copy my comment from dupe story that didn't get any traction.] The article avoids all the interesting technical details. In case you are wondering if this is possible and how much of this is an exaggeration, the title of the research article is "The Landscape of DNA and RNA Methylation Before, During, and After Human Space Travel (Twins Study - Mason) - 09.27.17" https://www.nasa.gov/mission_pages/station/research/experiments/2104.html https://www.nasa.gov/mission_pages/station/research/experime... Methylation is an usual process that the cells use for enabling and disabling genes expression. It's reversible, somewhat permanent and somewhat inheritable. If you like a bad analogy, it's like making a change in the bios setup of your computer or updating the configuration of the wifi-router. It's not a firmware upgrade or a hardware modification. More info: https://en.wikipedia.org/wiki/DNA_methylation https://en.wikipedia.org/wiki/DNA_methylation

psychobabble 9y ago
Oh heck, me too - since I was responding to your only comment just minutes ago, here is again :) Maybe, but what is really causing the DNA methylation? The article pins it mostly on epigenetics or environment, the 'stress of space travel', including dietary constraints and oxygen levels all of which are valid. - https://theconversation.com/epigenetics-can-stress-really-change-your-genes-55898 https://theconversation.com/epigenetics-can-stress-really-ch... - http://sitn.hms.harvard.edu/flash/2017/stress-induced-dna-modification-may-play-role-mental-illness/ http://sitn.hms.harvard.edu/flash/2017/stress-induced-dna-mo... - https://www.scientificamerican.com/page/sponsored/nestle/how-diet-can-change-your-dna/ https://www.scientificamerican.com/page/sponsored/nestle/how... ooh, sponsored article, didn't catch that the first time. However, the CNN article only briefly mentions 'radiation' as a factor and likely is lumping that into the 'stressful environment' case repeated several times. Realistically, cosmic rays or radiation are far more likely to the be prevailing indicator for DNA disruption but are not plainly disclosed here. Despite much research having been done on this specific topic. Wikipedia states: https://en.wikipedia.org/wiki/Health_threat_from_cosmic_rays https://en.wikipedia.org/wiki/Health_threat_from_cosmic_rays "The potential acute and chronic health effects of space radiation, as with other ionizing radiation exposures, involve both direct damage to DNA, indirect effects due to generation of reactive oxygen species, and changes to the biochemistry of cells and tissues, which can alter gene transcription and the tissue microenvironment along with producing DNA mutations." From this paper: https://arxiv.org/abs/1406.6641 https://arxiv.org/abs/1406.6641 "In the present paper, we suggest the BNR as a cause of genetic “fails” in living cells, that is one of the possible origins of the so called spontaneous mutations. Cells exposed to the shower of electrons and ions, caused by the collision of a neutron and a proton of water, could be annihilated or experience a permanent damage, in particular, a damage in the DNA." Cosmic radiation detrimental effects to DNA confirmed by NASA in this study: https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20080029284.pdf https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/200800... And more poignantly, from https://www.vencoreweather.com/blog/2017/6/26/1200-pm-cosmic-rays-continue-to-rise-as-solar-cycle-approaches-next-minimum https://www.vencoreweather.com/blog/2017/6/26/1200-pm-cosmic... ( do not read full link if you are easily panicked ): "... there are other consequences of increasing cosmic rays according to “Spaceweather.com” including the penetration of commercial airlines, dosing passengers and flight crews enough that pilots are classified as occupational radiation workers. [Dose rates are expressed as multiples of sea level. For instance, we see that boarding a plane that flies at 25,000 feet exposes passengers to dose rates ~10x higher than sea level. At 40,000 feet, the multiplier is closer to 50x]" Sorry for the data dump, I just happened to be researching cosmic ray effects the past few evenings and have collected many interesting facts on the topic. The most I have concluded at this point is that humans, as currently derived, are not made for space travel.

tofof 9y ago

From the Nasa press release, 93% of the genetic expression pattern (very different than "DNA") remained the same before and after spaceflight, while 7% was altered. Search for "93%" in https://www.nasa.gov/feature/nasa-twins-study-investigators-to-release-integrated-paper-in-2018 https://www.nasa.gov/feature/nasa-twins-study-investigators-...