The 7% change to Twin's Gene expression

SpaceNut · 2018-03-25 15:29:23

Kbd512 wrote:

NASA recently used a pair of identical twins, both astronauts, to study what happens to humans in space while aboard ISS for a year. 7% of the DNA of the man they sent there for a year changed over the course of that year. The only reason we know that today is because NASA procured an identical pair of willing human guinea pigs to see what happens when a human spends a year in space. Elon Musk had nothing to do with that and he's every bit as clueless about how well humans can live in .38g as everyone else is. All this experimentation isn't simply done because NASA likes spending money. They have to know certain things before they attempt other things that require basic knowledge about how well something is likely to work before many more billions are spent trying to do something that ultimately proves to be futile

Louis wrote:

4. NASA have spent $2.5 billion on one small Rover project. That could have been used to build a BFR type craft.
Talking of 7% DNA change is misleading as this article notes:
https://www.theverge.com/2018/3/15/1712 … ce-station
It was a minimal change in gene expression. And it's not clear exactly what related to the space flight. NASA had to issue a correction because this misinterpretation was circulating. But I blame NASA for spinning it in the first place - typical of them to try and give the impression that the impact of zero G is very negative.
Moreover the twin was in zero G for over one year. The Mars pioneers will be in zero G for six months or thereabouts and then be in recovery on Mars. There is no doubt in my mind that their muscle power will recover in the 0.38 G assisted by wearing weighted suits. This is a purely mechanical process. The origin of effects on the immune system are less clear. But they are unlikely to be life threatening, since no one has died after extended orbital zero G exposure, even over 400 plus days.

SpaceNut wrote:

I agree that the 7% DNA change is misleading as to what permanent damage will persist and become a cancer in the following decades.

SpaceNut · 2018-03-25 15:31:37

Kbd512 wrote:

There may be no permanent ill effects from the DNA changes. The point is, we don't know what the effect will be. Prior to shipping hundreds of people to Mars, do you think it might be a good idea to find out first? How about having people live the rest of their lives in .38g? Does anyone here know what the effect of that will be? If so, care to share what you see in your crystal ball with the rest of us? I'm sure NASA and Elon Musk would love to know.

SpaceNut wrote:

Crystal ball or not the Apollo and all past mission to present have all the data that is needed to say what will happen in space when the protection is not enough.
Space Radiation Is Becoming More Dangerous for Astronauts
NASA should update its radiation guidelines for astronauts, new research recommends, because there is now more accurate data about how space affects the human body.
Nathan Schwadron is a physics professor at the University of New Hampshire and lead author of a new study in the journal Space Radiation. Using an instrument on NASA's Lunar Reconnaissance Orbiter called CRaTER, his team found that rates of a certain kind of radiation in space are even higher than they previously predicted. This could pose a possible health risk for future voyages to the moon or Mars.
In recognition of the increased risk, Schwadron and several other radiation experts are working with NASA and other space agencies to revise radiation standards.
The European Space Agency allows its astronauts a lifetime maximum of 1 sievert of radiation, which is associated with a five percent increase in lifetime fatal cancer risk. NASA's guidelines are stricter, limiting astronauts to a three percent increase in cancer risk. By comparison, measurements from the Mars Curiosity rover in 2013 suggest an 860-day trip to Mars (including 500 days on the surface) would subject individual

kbd512 wrote:

SpaceNut
The cancer risk evaluation system is based on flawed notional suppositions of what would increase the risk of cancer, not sound scientific evidence backing the idea. That said, solar radiation is lethal at dose rates associated with SPE's.
NASA needs to give up on using BNNT as a structural material for the time being and use it as a non-structural liner instead. It's the best material we have available for radiation mitigation, by mass, and it's proven to effectively stop radiation. Failing that, PE foam is the next best shielding material and proven in space flight. Between the liner and a water wall, the protection afforded will have to suffice. An inflatable habitat with limited use of metallic components and a core section with a BNNT wrapped PE water tank is going to be as good as it gets for now. Active mitigation solutions can be tested now and employed later, when ready for prime time.

SpaceNut · 2018-03-25 15:34:22

SpaceNut wrote:

The 7% change is still not documented to what genes are altered or to what they may do for a persons future of having children or of Disease that are the chronic eventual outcome from exposure....
5 Serious Health Conditions That Can Be Passed Down Through Your Genes

SpaceNut · 2018-03-25 15:36:47

louis wrote:

I don't think the twins were monitored PRIOR to the zero G experience for the same length of time...you'd certainly need to do that to see what changes might or might not occur in 1 G over a similar period of time. But the 7% change was in gene expression, not genes.
SpaceNut wrote:
https://img-s-msn-com.akamaized.net/ten … =498&y=346
The 7% change is still not documented to what genes are altered or to what they may do for a persons future of having children or of Disease that are the chronic eventual outcome from exposure....
5 Serious Health Conditions That Can Be Passed Down Through Your Genes

SpaceNut · 2018-03-25 15:42:49

I just figured it was time to break the topic out to consolidate the discussion.... You have about 25,000 genes.

Understanding the Distinction Between Genes, DNA, and Chromosomes, Knowing the basics of genetics can help you understand genetic disorders

Humans have 23 pairs of chromosomes, resulting in 46 individual chromosomes. Of those pairs, one pair, the x and y chromosome, determines whether you are male or female, plus some other body characteristics. Females have an XX pair of chromosomes while men have a pair of XY chromosomes.

The other 22 pairs are autosomal chromosomes, which determine the rest of your body’s makeup.
https://en.wikipedia.org/wiki/DNA_repair#DNA_damage

DNA is made up of four similar chemicals—adenine, thymine, cytosine, and guanine. The particular order of the pairs of As, Ts, Cs, and Gs is extremely important in your DNA. Sometimes there is a mistake—one of the pairs gets switched, dropped, or repeated. This changes the coding for one or more genes and is called a genetic mutation. Some mutations are harmless, while other mutations can cause diseases or lead to nonviable pregnancies.
Another way your DNA code could be changed is by errors in your chromosomes. Parts of a chromosome could break off, switch with part of another chromosome, or be swapped within the same chromosome. If any of these or other mistakes occur then changes, also known as mutations, happen within the coding of your genes. You can also have three copies of a chromosome, known as a trisomy, or only one chromosome, instead of the normal pair. Down syndrome, also called trisomy 21, occurs when there are three copies of chromosome 21.

A gene is a short section of DNA. Each gene codes for a specific protein by specifying the order in which amino acids must be joined together.

http://www.cancerresearchuk.org/about-c … and-cancer

Genes that repair other damaged genes (DNA repair genes)
The DNA in every cell in our body is constantly in danger of becoming damaged. But cells contain many different proteins whose job is to repair damaged DNA. Thanks to these proteins, most DNA damage gets repaired immediately, with no ill effects.
But if the DNA damage occurs to a gene that makes a DNA repair protein, a cell has less ability to repair itself. So errors will build up in other genes over time and allow a cancer to form.
Scientists have found damaged DNA repair genes in some cancers, including bowel cancer.

https://en.wikipedia.org/wiki/Mutation

louis · 2018-03-25 16:42:39

I wouldn't claim to have even a basic understanding of genetics but I think I have got the idea that there is a difference between gene expression and DNA damage. Gene expression responds to your external and internal (body) environment. So, yes, we should expect gene expression to change when you go into zero G. But does your gene expression revert to "normal" after 5 years? We don't know yet.

SpaceNut wrote:

I just figured it was time to break the topic out to consolidate the discussion.... You have about 25,000 genes.
Understanding the Distinction Between Genes, DNA, and Chromosomes, Knowing the basics of genetics can help you understand genetic disorders
Humans have 23 pairs of chromosomes, resulting in 46 individual chromosomes. Of those pairs, one pair, the x and y chromosome, determines whether you are male or female, plus some other body characteristics. Females have an XX pair of chromosomes while men have a pair of XY chromosomes.
The other 22 pairs are autosomal chromosomes, which determine the rest of your body’s makeup.
https://en.wikipedia.org/wiki/DNA_repair#DNA_damage
DNA is made up of four similar chemicals—adenine, thymine, cytosine, and guanine. The particular order of the pairs of As, Ts, Cs, and Gs is extremely important in your DNA. Sometimes there is a mistake—one of the pairs gets switched, dropped, or repeated. This changes the coding for one or more genes and is called a genetic mutation. Some mutations are harmless, while other mutations can cause diseases or lead to nonviable pregnancies.
Another way your DNA code could be changed is by errors in your chromosomes. Parts of a chromosome could break off, switch with part of another chromosome, or be swapped within the same chromosome. If any of these or other mistakes occur then changes, also known as mutations, happen within the coding of your genes. You can also have three copies of a chromosome, known as a trisomy, or only one chromosome, instead of the normal pair. Down syndrome, also called trisomy 21, occurs when there are three copies of chromosome 21.
A gene is a short section of DNA. Each gene codes for a specific protein by specifying the order in which amino acids must be joined together.
http://www.bbc.co.uk/staticarchive/678f … 4374ff.jpg
http://www.cancerresearchuk.org/about-c … and-cancer
Genes that repair other damaged genes (DNA repair genes)
The DNA in every cell in our body is constantly in danger of becoming damaged. But cells contain many different proteins whose job is to repair damaged DNA. Thanks to these proteins, most DNA damage gets repaired immediately, with no ill effects.
But if the DNA damage occurs to a gene that makes a DNA repair protein, a cell has less ability to repair itself. So errors will build up in other genes over time and allow a cancer to form.
Scientists have found damaged DNA repair genes in some cancers, including bowel cancer.
https://en.wikipedia.org/wiki/Mutation

JohnX · 2018-03-26 10:29:22

Shouldn't we be looking at two effects here?
- effects of zero gravity on DNA
- effects of radiation exposure to DNA

I don't believe that the ISS is as well shielded from GCR & solar wind as a well-built Mars house would be. But long-term settlers would be there for more than 12 months. I can't do that kind of maths!
Up to 8 months in zero-G en route to Mars may still be the main exposure to weightlessness, but increased radiation on Marswalks and the effects of 1/3 G over long periods would be in the mix too.
I know I'm not at all quantifying this.

kbd512 · 2018-03-26 11:24:57

SpaceNut,

6 months later, the affected genes still haven't "responded" to the "new" Earth environment. That has to be at least a little troubling. It's a bit like the learning algorithms built into a vehicle's ECU.

GM makes two identical cars in the same factory and both vehicles contain the exact same parts. Even the color of paint used is the same. One vehicle is shipped to Colorado and the other is shipped to Texas. Using a computer program, their ECU's determine the O2 content in the air and adjust fuel input accordingly. Unfortunately, the program isn't "smart" enough to immediately determine that the O2 content of the air has changed when the vehicle delivered to the customer in Colorado is moved to a sea level location on an 18 wheeler. The ECU program figures that after driving for a year in thinner mountain air that the O2 sensor is simply malfunctioning when it claims that more O2 is available, so the ECU doesn't immediately re-adjust fuel input to optimize fuel economy at sea level. It just keeps signaling the fuel injectors to dump more fuel into the combustion chamber because the program's primary concern is not destroying the engine. If it runs too rich, the engine will still be fine. If it runs to lean, it'll fry the engine. Efficiency is less important than self-preservation.

I use that example because that is a real life example of how "environmental conditions" really do "condition" something as comparatively unsophisticated as an ECU program to take input, evaluate it, and then decide how to behave to preserve the system it's designed to safeguard. The ECU program's is trying really hard to "save" the engine, perhaps too hard in certain cases, much like an over-the-top autoimmune response to pollen in the air or gene expression changes intended to "prepare" their owner for the effects of microgravity and increased radiation levels.

The changes make the owner no less human than the next person, but they're clearly adapting their owner for a particular type of environment in the interest of survival. My concern is that the adaptations for one environment will never change, or may take many years to change, and that their owner will then function optimally only in the environment they're conditioned or adapted to. If there was some sort of faster learning algorithm built into our gene expression, perhaps something that takes 6 months to change instead of years or decades or multiple lifetimes, then that'd be less concerning.

The practical question then becomes, which car do you want to drive on a long duration road trip at sea level? One that's adapted for that environment or one that's not? I think it's worth further study. After we send people to Mars, they may become adapted to Mars and reverting back to a 1g environment may take many years. In simpler terms, after we send people to other planets, it may not be practical for them to ever come back. They may have to stay there permanently for their own health.

SpaceNut · 2018-04-24 22:34:48

It would seem that the spiral ladder of DNA is anything but perfect all the time as New DNA structure resembling a ‘twisted knot’ discovered in living human cells Scientists have tracked down an elusive 'tangled knot' of DNA

http://www.tiem.utk.edu/~gross/bioed/we … Aknot.html

https://www.space.com/40240-early-life- … rvive.html

GW Johnson · 2018-04-25 11:49:25

It is quite apparent that we do not understand yet all the consequences of longer-term exposure to zero-gee. Allow me to list what I think we know, based on what I read:

1. Bone decalcification and mass loss -- slowed but not reversed by exercise while exposed, reversed after returning to 1 gee.
2. Muscle weakness and mass loss -- slowed but not reversed by exercise while exposed, reverses after returning to 1 gee.
3. Weakening of the heart -- not yet sure whether exercise helps while exposed, seems (!!) to reverse after returning to 1 gee.
4. Loss of visual acuity -- seems to be at least partly irreversible; due to improper pressure gradient that is no longer imposed by gravity.
5. Weakening of the immune system -- nobody yet knows anything about why or how this occurs.
6. Genetic changes-- nobody yet knows why this occurs, or why it doesn't seem to reverse upon returning to 1 gee.

Louis's favorite solution of wearing weighted clothing on the moon or Mars might address the first two, nobody knows if it would help the third, and there is as yet no reason to believe it has anything to do with the price of tea in China regarding the fourth, fifth, and sixth items. Better than nothing I suppose, but not by much, if 4 misses out of 6 is any guide.

It seems intuitive that partial gee (like lunar or Martian gravity) might help maintain better health. Yet, because we were too stupid to investigate this with spinning space stations in orbit all these years, we have ZERO to base any predictions upon. It's just a guessing game.

All of the above is not a reason not to go into deep space (any destination). However, it IS a reason to supply artificial spin gravity when we go, to whatever extent is possible. The goal would be 1 gee's worth, until we have better information regarding the effects of longer-term exposures to partial gee. Because we evolved at 1 gee, we already know that level works. Simple as that.

Be aware that it is quite likely that yet more deleterious effects of zero-gee exposure long term will be discovered. I say that only because that has been the trend so far. In the 70's, only the first 2 on my list of 6 were known. The rest has been added slowly ever since.

The arguments against doing what I suggest (use spin gravity) depend primarily upon saving money (because doing spin gravity will cost a bit more, and will preclude some mission and vehicle designs). I contend that a good judge of character is whether someone prioritizes life over money, or they prioritize money over life. Makes a good rule of thumb in general, for me. (So many fail the test!)

GW

Last edited by GW Johnson (2018-04-25 11:55:54)

New Mars Forums

Announcement

#1 2018-03-25 15:29:23

The 7% change to Twin's Gene expression

#2 2018-03-25 15:31:37

Re: The 7% change to Twin's Gene expression

#3 2018-03-25 15:34:22

Re: The 7% change to Twin's Gene expression

#4 2018-03-25 15:36:47

Re: The 7% change to Twin's Gene expression

#5 2018-03-25 15:42:49

Re: The 7% change to Twin's Gene expression

#6 2018-03-25 16:42:39

Re: The 7% change to Twin's Gene expression

#7 2018-03-26 10:29:22

Re: The 7% change to Twin's Gene expression

#8 2018-03-26 11:24:57

Re: The 7% change to Twin's Gene expression

#9 2018-04-24 22:34:48

Re: The 7% change to Twin's Gene expression

#10 2018-04-25 11:49:25

Re: The 7% change to Twin's Gene expression

Board footer