[HN Gopher] Scientists found genetic mutations in every astronau...
___________________________________________________________________
Scientists found genetic mutations in every astronaut blood sample
they studied
Author : kiyanwang
Score : 136 points
Date : 2022-09-08 09:37 UTC (1 days ago)
(HTM) web link (futurism.com)
(TXT) w3m dump (futurism.com)
| acqbu wrote:
| The obvious question is: How is this different from non-
| astronauts being affected by mutagens like chemicals and
| radiation? Are there any statistical differences?
| 1970-01-01 wrote:
| >The samples were then cryogenically stored at -112 degrees
| Fahrenheit for around two decades.
|
| So "scientists" stored DNA for 20 years and _then_ decided to
| take a closer look? Better than nothing, but not by much.
| jostmey wrote:
| DNA sequencing wasn't an economically feasible option 20 years
| ago
| bergenty wrote:
| Well you're not addressing the GPs concerns. The DNA could be
| severely damaged.
| 1970-01-01 wrote:
| OK 20 years maybe it wasn't worth the cost, but by 2011 it
| was only thousands of dollars.
|
| https://www.genome.gov/about-genomics/fact-sheets/DNA-
| Sequen...
|
| https://en.wikipedia.org/wiki/DNA_sequencer#Comparison
| klyrs wrote:
| If they did analysis using tools and methods that weren't
| available / affordable 20 years ago, then preserving the
| samples for that long might have been wise.
| anarticle wrote:
| Ouch, it is not uncommon to freeze samples for a long time,
| especially rare ones like this. You're free to peruse the
| literature on how this is an accepted practice.
| 1970-01-01 wrote:
| So I did. Searched and read about it, found out the viability
| and recovery of cryopreserved PBMC has a clear downward
| slope. Samples are good for years, not decades.
| JoshTko wrote:
| Does anyone know if astronaut living quarters are designed to
| have equipment, water etc. placed in a way to maximize shielding?
| I.e a water tank that is shaped like a shell rather than a tank.
| amelius wrote:
| Question: in space, is the direction where radiation comes from
| distributed evenly, is all radiation coming from one direction,
| or something else?
| dr_orpheus wrote:
| A combination of directed and distributed evenly. There are 3
| (sort of 4) sources of radiation.
|
| 1. Trapped protons and neutrons in the Van Allen radiation
| belts. The ISS is well below the first Van Allen belt but it
| is really a continuous spectrum with peaks and valleys. For
| example there is the South Atlantic Anomaly where the inner
| radiation belt dips lower and flying through this region
| exposes you to more radiation. This is the fairly distributed
| radiation source
|
| 2. The sun. Solar storms, coronal mass ejections, all of
| these increase radiation. Although these may not be facing
| the sun as much as you might think. The radiation bends
| around the magnetic field of the earth so this often affects
| things closer to the poles of the Earth (and causes the
| Auroras) and spacecraft in high inclination orbits.
|
| 3. Galactic Cosmic Rays (GCRs). These are from far off events
| like supernovae or black holes but are really high energy. So
| direction is generally "from the galactic disk" but that is a
| pretty wide direction
|
| 4. Bremsstrahlung. This is basically radiation caused when
| one charged particle deflecting/slowing down another
| particle. The interaction causes some radiation (usually in
| the form of X-rays, or gamma rays if you get something coming
| in real hot) but basically comes out as the vector component
| of how the particle was deflected so it can be from a number
| of directions.
| https://en.wikipedia.org/wiki/Bremsstrahlung#In_astrophysics
| JumpCrisscross wrote:
| > _in space, is the direction where radiation comes from
| distributed evenly, is all radiation coming from one
| direction, or something else?_
|
| Mostly directionally from the Sun. Reflected radiation comes
| from the reflection surface. Cosmic background from dark sky
| (which isn't all directions if you're near a blocking body).
|
| That said, the point of these studies is to measure how much
| damage which kinds of radiation cause. So short answer, we're
| not sure. (But probably the Sun.)
| amelius wrote:
| Ok.
|
| Now I'm wondering, if you go from the space ship, say 1000
| km into the direction of the Sun, and then somehow apply a
| very small force to the radiation, would it be possible to
| make the radiation go past the space ship?
| JumpCrisscross wrote:
| > _then somehow apply a very small force to the
| radiation, would it be possible to make the radiation go
| past the space ship_
|
| For charged particles, yes. This is how the earth's
| magnetic field [1] protects us.
|
| [1] https://en.m.wikipedia.org/wiki/Earth%27s_magnetic_fi
| eld#Mag...
| elmomle wrote:
| While I don't know the answer, I'd think maintainability is the
| big constraint there. In the extreme case, imagine the
| difficulty of pinpointing and fixing any problem when all your
| systems are nested shells with a massive surface area. You'd
| need to take half the station apart any time something went
| wrong.
| natch wrote:
| That's the plan for trips to Mars. Water storage would be in a
| void between outer walls, creating a somewhat / partially
| protective barrier.
| jeisc wrote:
| Human beings are earthbound creatures and can live in space only
| with the mother ship earth... which we are working on destroying.
|
| Something might survive and thrive in space of course if it were
| properly designed for that.
| habibur wrote:
| Was expecting a number comparing the amount of mutation with a
| regular non-astronaut's genetic mutation. It's not there.
| [deleted]
| chromatin wrote:
| That information is relatively well known to those familiar
| with the field of clonal hematopoiesis, and was likely omitted
| for brevity. It is not reasonable to expect lay public level of
| background information to be included in every discipline's
| scientific publications.
|
| I'll point you to the two seminal papers in the field of CH
| though if you are interested. These were published back-to-back
| in the same issue of NEJM in 2014 (interestingly from separate
| competing groups at Harvard).
|
| https://www.nejm.org/doi/full/10.1056/nejmoa1408617
| https://www.nejm.org/doi/full/10.1056/nejmoa1409405
| jxramos wrote:
| I don't get it, how is it that the simple question of "compared
| to what?" is just completely omitted and seemingly never even
| considered by so many authors? Do people just operate with
| plain dead end facts without context or curiosity about how
| normal is even characterized or distributed? Is the idea of a
| nominal case/measure/etc so foreign? I wonder what series of
| basic questions could be memorized that could be a tool for
| authors to ask themselves to elicit getting this information or
| at least stating that the answers are unknown.
| hedora wrote:
| If I were on a tenure review board, I would argue against
| treating Nature papers as peer reviewed publications. I keep
| seeing obvious "strong reject" clickbait from them,
| specifically.
|
| This paper is a prime example.
| lostlogin wrote:
| Are you referring to the paper, or the summary of the paper
| which was linked to here?
| hedora wrote:
| The actual paper. It's the top link in the body of the
| article.
| michaericalribo wrote:
| I'm confused...did you read the Science paper itself? In
| their _first paragraph_ they reference baseline genetic
| variation, and age-related mutation versus the mutations seen
| in cancer survivors and--as it turns out--astronauts, in the
| second paragraph. Lots more details and caveats on the
| limitations of the data elsewhere in the paper.
|
| You seem to be reacting to this article, which is a popular
| summary of the findings. I don't even think it's a misleading
| article--it conveys the qualitative conclusion (elevated
| rates of nonstandard mutations), and answers to the questions
| you posed are available in the full scientific study...
| hedora wrote:
| The article links to a Nature paper. Are you reading a
| different paper?
|
| https://www.nature.com/articles/s42003-022-03777-z.pdf
|
| This is the closest thing I can find to a reference to a
| control in the first two paragraphs. The figures also
| suggest they did not have a control, so the use of the
| phrase "elevated rates" is baseless:
|
| > _Considering baseline genetic and extrinsic variability,
| the development of tools that permit the assessment of
| individual genetic susceptibility would improve risk
| stratification and long-term clinical management._
|
| If funded, that still wouldn't be a reasonable control.
|
| Maybe I'm missing a key sentence or something, but I've
| read the paper, and it seems to boil down to:
|
| "Mutations are bad, and this expensive piece of equipment
| measures mutations, so we stuck expensive astronaut blood
| in it, and the gauge pointed to a non-zero number".
| carbocation wrote:
| Would have been nice to see a comparison to alternates
| who were otherwise qualified but did not fly shuttles.
| michaericalribo wrote:
| Later:
|
| > Variants (SNP/ InDel) generated with this method were
| compared with a normal dataset using Archer's analysis
| pipeline to distinguish noise from a true call. The
| normal dataset was created with sequencing data from
| seven young, healthy individuals.
| hedora wrote:
| Archer's analysis pipeline isn't a well defined
| statistical test. It's a UI that browses results from the
| type of machine they used:
|
| https://www.enzymatics.com/news/archer-analysis-pipeline-
| upd...
|
| They filtered the results with various p-values < 0.01.
| Their supplementary data:
|
| https://www.nature.com/articles/s42003-022-03777-z#Sec9
|
| doesn't say how many samples the machine produced in the
| first place, but it does say the filter resulted in 35
| hits. That tells us absolutely nothing about the rate of
| mutations in the astronauts vs the general population, or
| even if astronauts produce more novel mutations on
| average vs. the general population.
|
| On top of that, they seem to have the data to answer
| these questions, but don't report it anywhere:
|
| Do zero-mission astronauts also show a "true call" in
| Archer's analysis pipeline?
|
| They ran multiple samples from the same astronauts
| (before and after missions). On average, does the same
| astronaut have more/more-novel mutations after each
| mission?
|
| These would require additional experiments or data, but
| seem obvious to check:
|
| Do they have unusually high or low numbers of mutations
| vs. the general population at the same age?
|
| If so, grouping the general population sample, what other
| professions also show a "true call" according to the
| pipeline?
| gus_massa wrote:
| From the article:
|
| > _in this astronaut cohort (median age 44 years, range
| 37-67),_
|
| I'd like to see also a comparison with 7 normal persons
| with ~45 years old. How many mutations is the expected
| value for a ~45 years old person?
| pcrh wrote:
| The article itself is full of caveats and concludes that
| their finding is inconclusive... Just some examples:
|
| >Overall, further longitudinal studies are required to
| characterize CH and somatic mutational profiles in the
| context of space flight-associated stressors and their
| associated clinical impact. To date, there is no evidence
| of relevant CVD, cancer, or neurodegenerative diagnoses
| associated with this given astronaut cohort (current median
| age 62.5 years (IQR 60-67)). The lack of longitudinal
| samples from these same astronauts limits the assessment of
| clone stability, pathogenic potential, and prognostic value
|
| But that the value of their report is in demonstrating the
| possibility of using stored archival blood samples in
| future studies:
|
| >Thus, this study serves to address the feasibility of
| using bio-banked astronaut samples and demonstrate the
| importance of collaborations between NASA's Human Research
| Program, Translational Research Institute for Space Health,
| Space Biology Program, NASA's clinical support teams and
| corre- sponding data and biorepository branches,
|
| Unfortunately, though, people far and wide are inevitably
| going to use this paper as evidence that space travel
| causes leukemia...
| csdvrx wrote:
| > The article itself is full of caveats and concludes
| that their finding is inconclusive... Just some example
|
| It's a bad example. Mutations are known to cause various
| health problems like cancer. It's like randomly writing
| to the RAM, live: maybe you won't crash the computer
| immediately, but keep trying and you'll do damages.
|
| The fact there's "no evidence of relevant CVD, cancer, or
| neurodegenerative diagnoses associated with this given
| astronaut cohort" shouldn't be surprising, given that
| astronauts are finely selected for perfect health among a
| large pool of candidate.
|
| It's like saying "it's totally ok to do drugs or
| performance enhancer when you're a sports professional
| player" - no, they will eventually degrade the pro player
| health too!
|
| Compared to a random person, it _might_ just show later,
| as they have more of a health capital.
|
| > Unfortunately, though, people far and wide are
| inevitably going to use this paper as evidence that space
| travel causes leukemia...
|
| Given everything we know, yes it should, among other
| things - just like writing to RAM should eventually crash
| a computer
| pcrh wrote:
| Mutations acquired during a lifetime are far more common
| that commonly believed; it's a key aspect of ageing. The
| astronauts in this study had an average age of 44, by
| which time they would be expected to have acquired
| mutations under normal, earthbound, conditions.
|
| To address this, the study compares the number of
| mutations found in the astronauts with the number found
| in a broader population with mean age of 58 yrs. Notably,
| they do not conclude that more mutations were found in
| the astronauts.
| whycombinetor wrote:
| I'm not following several different aspects of your comment
| here. First of all, the paper is in Nature, not Science.
| Second, the first and second paragraphs do contain some
| relevant words, but nothing quantitative - literally the
| only quantitative number (not nomenclature number) in the
| entire first 2 paragraphs is CHIP being defined as >2% of
| something. Furthermore the reference to baseline genetic
| variation you mention is verbatim as follows: "Considering
| baseline genetic and extrinsic variability, the development
| of tools that permit the assessment of individual genetic
| susceptibility would improve risk stratification and long-
| term clinical management."
|
| And I would argue that the article (not paper) does _not_
| convey the qualitative conclusion of elevated rates of
| nonstandard mutations, because it doesn't reference the
| baseline at all! It doesn't even present it as a
| comparison, like "We found MORE mutations in astronauts
| than would be expected of non-astronauts" - it literally
| just phrases it as "We found mutations in astronauts",
| which, considering that non-astronauts are exposed to
| radiation and get cancer + epigenetic mutations as well,
| doesn't differentiate it from the normal expected
| observation.
| michaericalribo wrote:
| You're eliding an entire body of research with ">2% of
| something." That assertion is cited, and links to a full
| study.
|
| This is an observational study, and you may be analyzing
| it as a designed one. There was no randomization, no
| large scale matched control group per se--that wasn't the
| intention. The intention is to analyze a specific
| population, and compare it to the existing literature on
| prevalence of mutations. That's how these things are
| done, you have to use the citations given to understand
| the broader context of a study. One study is not useful
| on its own.
|
| Also, there's this--they did hypothesis tests against a
| control group:
|
| > Variants (SNP/ InDel) generated with this method were
| compared with a normal dataset using Archer's analysis
| pipeline to distinguish noise from a true call. The
| normal dataset was created with sequencing data from
| seven young, healthy individuals.
| whycombinetor wrote:
| How am I eliding anything? My statement is that the only
| quantitative number in the first 2 paragraphs is the
| ">2%" figure.
|
| I'm also not criticizing the study, I'm criticizing the
| article and your defense of it. If "you have to use the
| citations given to understand the broader context of the
| study" - then if the point of a pop sci article is to
| effectively communicate the salience of the paper to lay
| audience, then that broader context needs to be
| communicated too.
| michaericalribo wrote:
| No reasonable person reads "found genetic mutations in
| every astronaut" to plausibly mean "found bog standard
| genetic mutations everyone's got." This is pop science
| communication--journalism--not the actual scientific
| study. The goal isn't scientific precision, it's
| democratizing technical work
| whycombinetor wrote:
| Really? I think everybody in the entire world knows
| somebody who's died from cancer, and the more educated of
| those people know that cancer is caused by genetic
| mutations. Also the theory of evolution is based on
| random genetic mutations - a very popular theory. I think
| a reasonable person would therefore know that everybody
| gets random genetic mutations over time.
|
| To put it concretely, if the chance of a random gene
| mutation is 10^-4 to 10^-6 per gene per generation, and
| there are 37 trillion cells in a human body, each cell
| containing about 20k genes, (all numbers from quick
| google searches) then the odds of having NO genetic
| mutations occur in your body in one day would be (forgive
| my back of the envelope math, assuming a generation is 20
| years): (1 - 10^-6)**(37 trillion * 20000 / 365 / 20). My
| calculator can't keep enough precision to make this
| nonzero. i.e., everyone has genetic mutations constantly
| which makes the title of the article completely
| uninformative.
| gus_massa wrote:
| There are some tricks to reduce the number of _important_
| mutations.
|
| Germinal cells reproduce very slowly, so the eggs and
| sperm have fewer mutations.
|
| Also, cells inside the guts have some cascade method. The
| cells near the wall reproduce very seldom, but the
| intermediate cells reproduce faster, and the inner cells
| reproduce even faster. The inner cells that are
| reproducing fast die or get washed away, so the big
| number of possible mutations is removed. And the slow
| reproducing cells near the wall create more cells to
| replace the intermediate cells that replace the inner
| cells.
| gatane wrote:
| The fantastic four were right after all. Space radiation is no
| joke.
| astrobe_ wrote:
| Joke aside, even for regular flight crews and passengers, it is
| a subject of concerns [1].
|
| [1] https://pubmed.ncbi.nlm.nih.gov/11603132/
| winternett wrote:
| The idea of how they recycle drinking water is also of high
| concern to me personally... What if the equipment breaks or
| underperforms?
|
| People constantly act as if science and technology is flawless
| in execution, but in reality it rarely is.
|
| There is also space radiation and other factors that can easily
| affect bio organisms, without any way of knowing what happened
| here on earth. COmpared to the ideals of Star Trek, we are
| still vastly primitive in terms of understanding space... Makes
| me kinda sad how much safety needs to be risked just to explore
| the outer bounds.
| possiblydrunk wrote:
| 20+ year old DNA samples, even stored deeply frozen, could
| accumulate damage that would be amplified during library prep
| prior to sequencing. To make the case, they would really need
| appropriate control samples from the same time periods stored
| under the same conditions.
| themanmaran wrote:
| It's also worth noting that the samples they used were from a
| totally different age bracket than the astronauts.
|
| Astronauts (aged 37-67) compared to "seven young, healthy
| individuals."
| [deleted]
| kklisura wrote:
| Layman question: Did gravity took any part on life creation on
| Earth? Do we even know if life or DNA can even form in non or low
| gravitational environment?
| mempko wrote:
| I think the closest to a 'low gravity' environment is the
| oceans. So I suspect yes, life would form in low gravity
| environments. It would likely have more rotational symmetry vs
| mirror symmetry land animals have. You see a hint of that in
| ocean life where things are more...round.
| Maursault wrote:
| > I think the closest to a 'low gravity' environment is the
| oceans.
|
| The oceans are not a low gravity environment, and gravity is
| no less when floating in water. Depending on the density of
| the water and the object that is floating, it is buoyancy
| that causes floating in water. Gravity works the same on the
| floater and the water.
|
| And we could correctly assume gravity is essential for life,
| as without gravity, not even the Earth would not revolve
| around the Sun, let alone whatever it is that life is
| supposed to form on in low gravity, and we know that light is
| essential for life.
| earleybird wrote:
| Now you've got me wondering - what is the difference between
| buoyancy and low gravity (with respect to organism
| development/evolution)? Would there be any meaningful
| differences structurally?
| teeray wrote:
| I would think yes. In a submarine, the vessel is buoyant,
| yet the contents are subject to regular gravity. I think
| the same reasoning applies to a body and its organs and
| fluids. Contrast with space where everything floats.
| [deleted]
| temp12192021 wrote:
| Most sealife has mirror symmetry though, doesn't it?
|
| I guess jellyfish, urchins meet the rotational symmetry
| though.
| Spooky23 wrote:
| That's about aerodynamics (hydrodynamics?), as water is
| more resistive than air.
| mtlmtlmtlmtl wrote:
| It's still an open question how life formed from non-life(look
| up abiogenesis).
|
| It's also an open question whether it formed on Earth at all or
| came here from elsewhere.
|
| So there is no answer to your question as yet. Or at least
| there's no scientific consensus on one.
| midjji wrote:
| We know DNA and and even semi self replicating biochem
| molecules can form both in the presence and absence of gravity.
| It requires a suitable energy gradient though, and I like the
| idea that cyclical changes in the energy gradient are required
| for evolution to occur rather than stagnating in a specific
| state. This is partly why tidepools are an interesting
| candidate for early life.
| blueprint wrote:
| it's pretty certain that life in this form would not have
| formed without gravity though.
| anigbrowl wrote:
| This links to a (much better) better press release which in turn
| links to the original study.
|
| https://www.newswise.com/articles/researchers-find-spaceflig...
|
| https://www.nature.com/articles/s42003-022-03777-z.pdf
|
| OP - and HN readers in general - please consider _not_ submitting
| the first article you find on an interesting topic. Follow the
| links back and submit the _best_ version you can find. You do not
| owe the clickbait outlet any sort of reward just because they
| promoted a bit of interesting news onto your radar. If there
| weren 't so much clickbait, quality news would stand out much
| more easily.
|
| Science writers, maybe you want to inform the public by making
| information simple and accessible to a general audience. That's
| good. But if you just give them factoids and don't include any
| scientific reasoning (like a comparison to the baseline, or
| noting the absence of one) then you're just selling sugary snacks
| that are not really very nutritious.
| swatcoder wrote:
| I agree with the sentiment of tracing a headline back to the
| topic's best coverage.
|
| But posting plain studies directly to non-industry forums is
| often not ideal. The studies are not written for a general
| audience and rely on jargon, shorthand, assumptions, and shared
| education that general audience readers are _at least_ as
| likely to misinterpret as professional science writers.
|
| We like to beat up on science writers for writing poor and
| misrepresentative coverage of research, but are you sure a
| bunch of random (and often compulsively contrarian)
| intellectuals trying to earn internet points are an
| improvement?
|
| The best of both worlds is probably to find the best coverage,
| and then add the study in a comment.
| nightpool wrote:
| The GP said that you should submit the _best_ article on any
| given topic, not just the original study. In fact, they
| specifically called out the press release by the original
| authors (which can be viewed on Mt Sinai 's blog: https://www
| .mountsinai.org/about/newsroom/2022/fesearchers-f...) as
| being "much better" then the original article. I'm not a
| researcher, but as a member of the public I also agree that
| the press release seems to do a good job at explaining things
| for the public while also not dumbing things down or
| exaggerating the findings too much. Nobody is saying you
| should just post the original study devoid of any context
| swatcoder wrote:
| Totally. I wasn't challenging the GP, just elaborating on
| nuance.
| dpifke wrote:
| dang has said that HN doesn't outright ban TV news sites like
| CNN, despite being against the guidelines[0], because they do
| occasionally surface interesting stories.
|
| But every example of that I've seen has essentially been
| blogspam that is better covered by primary sources instead. I
| really wish he'd reconsider.
|
| [0] "If they'd cover it on TV news, it's probably off-topic."
| https://news.ycombinator.com/newsguidelines.html
| toastedwedge wrote:
| My rule of thumb is find a balance between "getting to the
| point" and accuracy. A study by itself in a specialized field
| will only be intelligible by a select group, but a science-
| based news site that can condense it appropriately is my goto.
| anoncow wrote:
| > If there weren't so much clickbait, quality news would stand
| out much more easily.
|
| So much this. I took a break from some news websites a few
| years back, when I recently visited one of them, I was sad to
| see that many front page news articles had clickbait titles.
| kingkawn wrote:
| Somehow each generation is convinced anew that their pearl
| clutching will be of any interest to others
| mabbo wrote:
| Setting aside the question of "compared to what?" (I presume they
| mean "more than normal folk"), I think it's more fun to
| brainstorm the question of "what could be done to prevent this?"
|
| I'm guessing that the mutation danger is because space is just
| full of radiation that various layers around the earth give us
| partial protection from. So what can be done in a hypothetical
| spacecraft to get the same level of protection?
|
| If we want to send people to Mars, or live in large numbers in
| space, these are fundamental problems to solve.
| [deleted]
| mxkopy wrote:
| Of the proposed solutions, this one is my favorite:
|
| https://en.wikipedia.org/wiki/Radiotrophic_fungus
|
| I'd like to think that in this universe the best spacecraft
| asymptotically approach being a mushroom
| mabbo wrote:
| Oh that is a _delightful_ idea.
|
| Now if we could breed them to also somehow produce usable
| fuel as a means of energy storage...
| amelius wrote:
| And the control group?
| fsniper wrote:
| And how can we rule out that the mutations are not introduced
| in time at rest? All these blood samples are more than 20 years
| old.
| michaericalribo wrote:
| Maybe the scientists manufactured the data with CRISPR. /s
|
| In seriousness, we can come up with lots of out-there
| scenarios. But this finding is intrinsically interesting
| enough to warrant discussion, critique, and further analysis.
|
| Your critiques aren't a failure of the system, or a "dunk" on
| the scientific establishment. This open, democratic dialogue
| is _the entire point of the scientific publication process._
| fsniper wrote:
| I am actually not critical of the deductions.I never even
| considered bad intentions.
|
| Being skeptical is required to get to reality. Do we really
| know if the storage procedures/ thawing procedures can't
| have a side effect of mutations on the samples? We are
| still learning too much about the epigenetics and we
| already know low temperatures can have adverse effects on
| tissues. So I just voiced my idea on this.
| onychomys wrote:
| Mutations are caused by errors in DNA repair mechanisms.
| Radioactive particles smash into DNA, breaking the bonds that
| hold it together. You have a whole system for DNA repair in
| your cells, but it's not 100% accurate, and so the more times
| you have to repair things, the more errors you're going to
| see.
|
| And the reason you'll never see it in random frozen samples
| from 20 years ago is that your cells have to be alive for it
| to happen, and those ones aren't.
| midjji wrote:
| Thing is, if your freze something, that does not stop its
| internal decay due to radiation, e.g. carbon 14, kalcium
| etc, its just that the errors which occur arent multipled
| and the relatively short time is insufficient. But freeze a
| corpse for a millenia and it will turn into swiss cheese
| from self radiation, even if it was healthy when you froze
| it.
| [deleted]
| fsniper wrote:
| Well you are right when you consider that a "mutation" can
| just be caused by the DNA copy/repair mechanisms. But what
| if a chemical degradation could also cause it? Perhaps a
| sample dna lost bases and the sequencing read the resulting
| base sequence as a new mutated sequence? I am just being
| skeptical.
| flobosg wrote:
| The samples were stored at -80degC, where any chemical
| degradation process would be slowed down immensely if not
| come to a virtual halt.
| bell-cot wrote:
| +10 if I could. Especially since the article notes that such
| mutations can be caused by "exposure to excess ultraviolet
| radiation". AKA sunburn?
| midjji wrote:
| There is a difference in where the mutations occur in the
| body. Sunburn still primarily causes mutation in and near the
| skin. radiation can cause mutations in the organs deeper in
| the body which are less robust against radiation, for the
| exact reason that the skin is usually a sufficient barrier.
| michaericalribo wrote:
| I mean, yes, sunburn is excess ultraviolet radiation, but
| there are lots of other (more severe) forms and it's pretty
| straightforward to understand they mean "excess [beyond the
| type experienced in the comparison populations, namely, the
| general population, who tend to experience minor exposure to
| excessive ultraviolet radiation, aka sunburn]."
|
| This isn't the "gotcha" you think it is.
| csdvrx wrote:
| See the twin study, as mentioned by someone else.
| areoform wrote:
| From the paper,
|
| > We obtained de-identified whole blood samples from 14
| astronauts who flew relatively short Space Shuttle missions
| (median 12 days) between 1998-2001. These samples were stored at
| -80degC for ~20 years. Blood samples were collected 10 days
| before flight, the day of landing, and 3 days after landing12.
| However, for this specific study, only samples from 3 days after
| landing (R + 3) were collected as buffy coats (peripheral blood
| mononuclear cells - PBMCs).
|
| One of the issues here is of the biased sample set. To say that
| astronauts are drawn from a small pool is a severe
| understatement. All astronauts from the stated era have,
| - High IQs - Absence of obvious psychopathologies
| - Extremely high stress tolerance - Faster (than the
| median) reaction times well into middle age - Usually
| within 3SD for M/F height, falling between 5' to 6'2 (6'4 at
| most) - High educational attainment
|
| And they've all done, - Scuba diving (sometimes
| including extended stays as aquanauts) - Pilot training
| (even if you're a scientist astronaut, they'll teach you how to
| fly, [edit - as Walter points out flight hours equal radiation
| exposure and NASA astronauts usually have to maintain a minimum
| of 180 hours per year to retain their flight status]) -
| *At least* one sport where they've risked their life -
| Undergone wilderness survival training, including a "hell week"
| of some sort, somewhere along the line - Experienced near
| drowning (part of training) and other similar stressors -
| (frequently but not always) Been a part of the military,
| including exposure to pollutants that we now know are
| carcinogenic or harmful.
|
| Additionally, during this period, unless they were an
| international astronaut, - They would eat
| similar foods, from the same places - Live in close
| proximity to each other - Grow up in roughly similar
| environments (though split between urban/rural environments)
|
| Of course, not all of these factors will impact their DNA, but
| the selection and similar life experiences creates a unique
| problem. Until we send more people up, we won't have enough data
| to say how space travel impacts and mutates us.
| WalterBright wrote:
| People who fly a lot get significant cosmic radiation exposure.
| gz5 wrote:
| From the linked Nature article, my layman's interpretation is it
| seems a more severe finding (CHIP) was not found (and was
| possibly what they were looking for as CHIP may have indicated a
| potentially more material impact), and that this is more like an
| early, thin data set which can't be fully evaluated without more
| data:
|
| >We identified 34 nonsynonymous SNVs in 17 known CHdriver genes,
| of which TP53 and DNMT3A were the most frequent. Notably, clone
| size was small, ranging from 0.10% to 0.95% VAF, and thus did not
| achieve the technical threshold to be considered as CHIP
|
| and
|
| >Due to the lack of longitudinal samples and small sample size,
| conclusions regarding the implications of observed lesions remain
| limited, and further studies are required to assess the
| penetrance of these clones.
|
| Is that how the rest of you read this, especially those of you
| who are more expert?
| Nokinside wrote:
| NASA astronauts Mark and Scott Kelly are identical twins and
| scientists took the opportunity to do extensive tests with
| them. One pair of twins is not conclusive but the study is
| interesting.
|
| The NASA Twins Study: A multidimensional analysis of a year-
| long human spaceflight
| https://www.science.org/doi/10.1126/science.aau8650
|
| NASA Twins Study Confirms Preliminary Findings
| https://www.nasa.gov/feature/nasa-twins-study-confirms-preli...
| michaericalribo wrote:
| I agree; that is basically my take, with two slight amendments:
|
| I didn't have the sense there was a value judgement (more/less
| severe), so much as that CHIP is "typical" mutation seen in the
| wider population, associated with aging (itself a fascinating
| field of research), whereas something novel / nonstandard is
| causing CH mutations (space?? That's the implication).
|
| On sample size, I read it as "this is interesting preliminary
| work that is surprisingly robust for the sample we have, and
| thus intrinsically notable." But the passage you cite and the
| surrounding discussion indicates that this is far from
| conclusive--it's a promising / interesting direction for more
| research to find out what's the "there" there, if anything.
|
| These things _could_ be coincidental, but such a high rate of
| consistency is strong signal to investigate further. This paper
| propagates that surprising result, which is also a unique
| analysis because of the lack of data the authors acknowledge.
| Without publishing this, others would have no access to even
| this preliminary finding.
| gnfargbl wrote:
| The actual study can be read at
| https://www.nature.com/articles/s42003-022-03777-z.pdf.
|
| Methodology is given towards the end of the paper. In particular:
| _" Variants [...] were compared with a normal dataset [...]
| created with sequencing data from seven young, healthy
| individuals."_
| Maursault wrote:
| Depending on the actual scope of the study (how many they
| sampled), even if samples were anonymously labeled, publication
| is a bound to be a violation of the Federal Privacy Rule
| protecting astronauts' right to medical privacy.
| kingkawn wrote:
| I should hope that the general plasticity of an organism would
| kick in when the environment so fundamentally shifts
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