5 ms·

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 t

by 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
  - tmsldd 9y ago
    Thanks for the analogy, I’m actually copying & pasting for future references ;)
  - Retric 9y ago
    It's arguably much closer to RAM than a make file. Picture a Glucose detector wrapped around a DNA segment that encodes something to break down Glucose. If you zero Glucose inside the nucleus you stop producing stuff to deal with it. The difference for this analogy is cells never stop compiling. On the other hand if you think of cell division as a reboot it's a better fit.
  - fnl 9y ago
    Your epigenetic state very much starts off inherited from your parents. Also, it's not just a gene switch, and in fact that probably is it's least relevant role, if any. Rather, and besides being a hereditary factor, it determines the structure/packing of your nucleosomes, and therefore determines the integrity of your cell as a whole, not just your gene expression levels.
- clon 9y ago
  Genes are the data, epigenetics talks about the program instructions, notably proteins called transcription factors. The latter are of course also encoded for in genes. The similarities to Von Neumann architecture are .. unsettling.
- db48x 9y ago
  Every gene can have a tag attached to it which prevents the gene from being used to create RNA (the tag is a methyl group, so this is called "methylation"). Since the RNA would then be used as instructions for creating a protein molecule, inactivating a gene by tagging it generally causes the cell to stop producing particular proteins. Since each protein has one or more specific jobs to do in the cell, this causes the behavior of the cell to change. There are a huge number of known proteins (millions maybe? I don't actually know), and a vast potential number of proteins (if you just consider all possible ways of arranging the 20 amino acids into a chain), so there are a vast number of ways that cell behavior can change over time. Indeed, this is how we manage to have different types of tissues at all, including our very complicated immune system with cells that act autonomously to protect against disease. Also, it's well established that there are plenty of feedback loops here. An active gene can code for the production of a protein that activates or inactivates other genes. There are numerous pathways by which external stimuli can amplify or inhibit all of these feedback loops, so external conditions often result in changes to which genes are tagged. As you can imagine, the state-space of all of this is immense; far larger than just the number and type of genes that you have. Mapping it all is a vast project that might easily take thousands of years.
  - ggoss 9y ago
    The well goes deeper still. Another mode of epigenetic regulation involves histones, the proteins around which DNA is wrapped, and the many ways they can be modified (by methylation, acetylation, ubiquitiylation, sumoylation, etc.). Both DNA methylation and histone modifications modulate how DNA wraps around histones, and thus how readily any given segment can be accessed and transcribed into RNA (and eventually translated into a given protein). This barely scratches the surface. This process, along with others that modify how DNA is folded, brings certain genes closer together (while moving others farther apart), increasing (or decreasing) the likelihood of all sorts of first, second, and third order (...) interactions between them and their products. And we've only just begun...
    - psychobabble 9y ago
      > This well goes deeper still > This barely scratches the surface. This process, along with others that modify how DNA is folded, brings certain genes closer together (while moving others farther apart), increasing (or decreasing) the likelihood of all sorts of first, second, and third order (...) interactions between them and their products. > And we've only just begun... Horribly vague, care to elaborate mathematically or at least provide some study links? The 'DNA folding' you propose begs resolution from some study using quaternions or attractors, or ... ?
- fouc 9y ago
  I know about epigenetics because of many articles in Popular Science or Discovery.
- nemacol 9y ago
  Youtube's SciShow gave me my introduction to epigenetics. Perhaps the science has advanced since this video was created, but I think it is a fine primer on the subject. https://www.youtube.com/watch?v=kp1bZEUgqVI https://www.youtube.com/watch?v=kp1bZEUgqVI
Erlangolem 9y ago
I think the issue for the article is that identical twins are not epigenentically identical to begin with, time in space and life in general will only tend to magnify that. In essence, the headline is doubly misleading.
mrmondo 9y ago
While I think it’s important to disagree with news that might be less than factual and better yet - think with a skeptical mindset, I think it’s rather anti-intellectual to blanket misleading or factually lacking news as ‘fake news’.
- Elrac 9y ago
  Good thing he didn't do that!
im3w1l 9y ago
> would be astounding if all the trillions of cells in your body underwent the same genetic mutations. spoiler: they won't all undergo the same epigenetic changes either.
- emiliobumachar 9y ago
  Are you sure? Might there be a coordination mechanism of sorts?
koonsolo 9y ago
Ok, that explains a lot, because my imagination was going wild with these 2 things: According to the article: 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. According to my memory, and now looked it up: Chimps and bonobos in particular take pride of place as our nearest living relatives, sharing approximately 99 percent of our DNA, with gorillas trailing at 98 percent. Good thing they put a picture in the article of the guy, haha.
- grondilu 9y ago
  > According to my memory, and now looked it up: Chimps and bonobos in particular take pride of place as our nearest living relatives, sharing approximately 99 percent of our DNA, with gorillas trailing at 98 percent. I thought of that as well while reading about the 7% they mention, but then I assumed they were talking about 7% of the genes that are specific to human kind.
  - vkou 9y ago
    Indeed. If 7% of your genome were replaced with something else, it would be incredibly unlikely that you would still be alive.
    - grondilu 9y ago
      Though now that I think about it, if 7% of the human-specific genome was changed, then it must mean that 7% of the rest was changed too. I mean it's not like cosmic particles specifically target human genes, is it?
teekert 9y ago
Exactly, I would expect this person to perhaps have some additional mutations (in his superficial tissues so no body wide mutation of course) due to radiation, or perhaps due to selective pressures working differently on them in 0 G. Also I'd expect expression changes (RNA quantity changes), also related to 0 G or maybe to his diet. Also, it is often claimed that chimp DNA is only 1% different from ours. Which is also bull of course, it depends, (as here) on how difference is defined. The telomere story is interesting but from the text it sounds like we already expect that from radiation and calorie restriction.

by loufe 9y ago

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
- tmsldd 9y ago
  Thanks for the analogy, I’m actually copying & pasting for future references ;)
- Retric 9y ago
  It's arguably much closer to RAM than a make file. Picture a Glucose detector wrapped around a DNA segment that encodes something to break down Glucose. If you zero Glucose inside the nucleus you stop producing stuff to deal with it. The difference for this analogy is cells never stop compiling. On the other hand if you think of cell division as a reboot it's a better fit.
- fnl 9y ago
  Your epigenetic state very much starts off inherited from your parents. Also, it's not just a gene switch, and in fact that probably is it's least relevant role, if any. Rather, and besides being a hereditary factor, it determines the structure/packing of your nucleosomes, and therefore determines the integrity of your cell as a whole, not just your gene expression levels.
clon 9y ago
Genes are the data, epigenetics talks about the program instructions, notably proteins called transcription factors. The latter are of course also encoded for in genes. The similarities to Von Neumann architecture are .. unsettling.
db48x 9y ago
Every gene can have a tag attached to it which prevents the gene from being used to create RNA (the tag is a methyl group, so this is called "methylation"). Since the RNA would then be used as instructions for creating a protein molecule, inactivating a gene by tagging it generally causes the cell to stop producing particular proteins. Since each protein has one or more specific jobs to do in the cell, this causes the behavior of the cell to change. There are a huge number of known proteins (millions maybe? I don't actually know), and a vast potential number of proteins (if you just consider all possible ways of arranging the 20 amino acids into a chain), so there are a vast number of ways that cell behavior can change over time. Indeed, this is how we manage to have different types of tissues at all, including our very complicated immune system with cells that act autonomously to protect against disease. Also, it's well established that there are plenty of feedback loops here. An active gene can code for the production of a protein that activates or inactivates other genes. There are numerous pathways by which external stimuli can amplify or inhibit all of these feedback loops, so external conditions often result in changes to which genes are tagged. As you can imagine, the state-space of all of this is immense; far larger than just the number and type of genes that you have. Mapping it all is a vast project that might easily take thousands of years.
- ggoss 9y ago
  The well goes deeper still. Another mode of epigenetic regulation involves histones, the proteins around which DNA is wrapped, and the many ways they can be modified (by methylation, acetylation, ubiquitiylation, sumoylation, etc.). Both DNA methylation and histone modifications modulate how DNA wraps around histones, and thus how readily any given segment can be accessed and transcribed into RNA (and eventually translated into a given protein). This barely scratches the surface. This process, along with others that modify how DNA is folded, brings certain genes closer together (while moving others farther apart), increasing (or decreasing) the likelihood of all sorts of first, second, and third order (...) interactions between them and their products. And we've only just begun...
  - psychobabble 9y ago
    > This well goes deeper still > This barely scratches the surface. This process, along with others that modify how DNA is folded, brings certain genes closer together (while moving others farther apart), increasing (or decreasing) the likelihood of all sorts of first, second, and third order (...) interactions between them and their products. > And we've only just begun... Horribly vague, care to elaborate mathematically or at least provide some study links? The 'DNA folding' you propose begs resolution from some study using quaternions or attractors, or ... ?
fouc 9y ago
I know about epigenetics because of many articles in Popular Science or Discovery.
nemacol 9y ago
Youtube's SciShow gave me my introduction to epigenetics. Perhaps the science has advanced since this video was created, but I think it is a fine primer on the subject. https://www.youtube.com/watch?v=kp1bZEUgqVI https://www.youtube.com/watch?v=kp1bZEUgqVI

Erlangolem 9y ago

I think the issue for the article is that identical twins are not epigenentically identical to begin with, time in space and life in general will only tend to magnify that. In essence, the headline is doubly misleading.

mrmondo 9y ago

While I think it’s important to disagree with news that might be less than factual and better yet - think with a skeptical mindset, I think it’s rather anti-intellectual to blanket misleading or factually lacking news as ‘fake news’.

Elrac 9y ago
Good thing he didn't do that!

im3w1l 9y ago

> would be astounding if all the trillions of cells in your body underwent the same genetic mutations. spoiler: they won't all undergo the same epigenetic changes either.

emiliobumachar 9y ago
Are you sure? Might there be a coordination mechanism of sorts?

koonsolo 9y ago

Ok, that explains a lot, because my imagination was going wild with these 2 things: According to the article: 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. According to my memory, and now looked it up: Chimps and bonobos in particular take pride of place as our nearest living relatives, sharing approximately 99 percent of our DNA, with gorillas trailing at 98 percent. Good thing they put a picture in the article of the guy, haha.

grondilu 9y ago
> According to my memory, and now looked it up: Chimps and bonobos in particular take pride of place as our nearest living relatives, sharing approximately 99 percent of our DNA, with gorillas trailing at 98 percent. I thought of that as well while reading about the 7% they mention, but then I assumed they were talking about 7% of the genes that are specific to human kind.
- vkou 9y ago
  Indeed. If 7% of your genome were replaced with something else, it would be incredibly unlikely that you would still be alive.
  - grondilu 9y ago
    Though now that I think about it, if 7% of the human-specific genome was changed, then it must mean that 7% of the rest was changed too. I mean it's not like cosmic particles specifically target human genes, is it?

teekert 9y ago

Exactly, I would expect this person to perhaps have some additional mutations (in his superficial tissues so no body wide mutation of course) due to radiation, or perhaps due to selective pressures working differently on them in 0 G. Also I'd expect expression changes (RNA quantity changes), also related to 0 G or maybe to his diet. Also, it is often claimed that chimp DNA is only 1% different from ours. Which is also bull of course, it depends, (as here) on how difference is defined. The telomere story is interesting but from the text it sounds like we already expect that from radiation and calorie restriction.