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NASA Confirms Discovery of Organism With Phosphorus-Free DNA
GNUALMAFUERTE writes "As we mentioned before, NASA's Department of Astrobiology had an important announcement to make today. It looks like Gizmodo was right. You can watch the presentation online right now. It looks like the bacteria in question uses arsenic as a phosphorus replacement in its DNA."
It's life Jim, but not as we know it.
This is neat and clearly an important discovery and all, but I'd be lying if I said I wasn't a little bit disappointed.
Someone get a fire engine, some Selenium, and David Duchovney.
-- IANAL, this isn't legal advice, and definitely isn't legal advice for you. Also, Squee!
It replaces MOST phosphorus atoms with arsenic, but not all.
This is sure to shut up all those naysayers who accuse NASA of being a waste of resources...
Apparently they have a invested in a pretty good network though. I was surprised that the video stream didn't cut out at all considering that there could be tens of thousands if not more watching.
NASA has really started to irritate me, with their latest few announcements. Rather than just issuing the data and having a little show about its implications in NASA TV, they first make an announcement that they will make an announcement, then for a few weeks there is rampant speculation (even though it's entirely probable that the data is ready) and finally they make their announcement in a media-circus style event.
NASA should just make the damn announcements on their web site and on their TV channel, and let the science press (read: science tabloids) publish it as they will.
If their current trend continues, pretty soon NASA will be announcing their announcement of their announcement of a press conference to announce their data. It's a waste of time and energy for everybody. I don't know about you, but I simply want my news, I don't want news that there will be news of note in the near future.
It wasn't phosphorus free, in fact they hadn't confirmed how much of the phosphorus had been substituted with arsenic, but they did mentioned it was not 100%. They also mentioned it was more than just DNA (ATP was also mentioned, although they implied more).
According to this NYT article this is a normal earthly bacterium that, when placed in an environment full of arsenic, started swapping arsenic for phosphorus. It's not a totally new form of life unrelated to what we know.
How I am supposed to poison the darn thing now??!?!
how long until
NASA has discovered a completely new life form that doesn't share the biological building blocks of anything currently living in planet Earth, using arsenic to build its DNA, RNA, proteins, and cell membranes. This changes everything.
That is not the case. The DNA is largely the same, except that phosphorous has been exchanged with Arsenic. Don't get me wrong, this is still a hugely interesting discovery, but it was implied during the pre-conference speculation that this was an entirely separate instance of abiogenesis, and that is simply not the case, unfortunately.
The discovery of this microorganism that can use arsenic to build its cellular components may indicate that life can form in the absence of large amounts of available phosphorus, thus increasing the probability of finding life elsewhere in the universe. The find gives weight to the long-standing idea that life on other planets may have a radically different chemical makeup and may help in hunt for alien life.
The more we think we know about, the greater the unknown... -Neil Peart
He who knows best knows how little he knows. - Thomas Jefferson
Wolfe-Simon's team took mud containing bacteria from the arsenic-rich Mono Lake and grew them in ever decreasing concentrations of phosphorous. Their rationale was that since arsenic is just below phosphorous in the periodic table, and shares many of its chemical properties and is even used as a source of energy for some bacteria, the bugs would be able to swap one for the other. That is just what happened.
From the New Scientist article. While it's possible, it hasn't been found in nature. The article also mentions why it might be unlikely. http://www.newscientist.com/article/dn19805-arseniceating-bacteria-point-to-new-life-forms.html
.Steven Benner, a chemist from the Foundation for Applied Molecular Evolution in Gainesville, Florida, who works on alternative forms of DNA, is sceptical that the bacteria really do contain arsenic. "I doubt these results," he says, since in order to measure the modified DNA it has to be put into a water-containing gel, which would rapidly dissolve any arsenate molecules. Any hypothesis that arsenate might replace phosphate in biomolecules must take this into account, he says.
This wasn't "bred" or modified by the scientists from an existing bacterium, it was occurring naturally in Mono Lake and was transported to the lab for concentrated study. That was the second-to-last question answered in the NASA TV broadcast.
since the general public will be goings "Arse-whaat"
No. That's what your mom said.
It is more evidence to support the hypothesis that life could be made from different elements than the ones that life as we know it are made from. Your DNA, like most living organisms' DNA, is made from five elements: hydrogen, carbon, nitrogen, oxygen, and phosphorus. This is evidence that DNA could be made using arsenic instead of phosphorus, which has similar chemical properties.
Personally, I think it would have been more exciting if they had discovered silicon based life, which would be a life form that uses silicon instead of carbon, but this is cool too...
Palm trees and 8
My thoughts are as follows:
THIS IS BLOODY AMAZING! followed by a little more tempered cogitation:
Arsenate is a triprotic species just like phosphate, each has a valence of +5, and it's directly one period down on the table so available electron shells in ground state will appear very similar. However arsenic possesses filled d orbitals and is about 7% less electronegative than phosphorous - these factors, among others, tend to make arsenate a little more reactive than phosphate which would make it less stable as a backbone of DNA. So if the degree of replacement is as thorough as NASA claims (they said they cultured it with zero phosphorous present - so only trace impurities) the cell has either found a way to strengthen the backbone or has developed an amazing repair mechanism which can deal with frequent DNA damage.
NASA has two summaries here and here.
Astrobiology has an article here.
And http://www.sciencemag.org/">Science will release a paper later today.
because this confirms many unproven ideas that not all "life" is in the same form as we are a custom too - other than this.. all life that we knew before now on earth used the same base DNA structure..
basically they have found life.. not as we know it.. and means that some of our methods for proving there isn't life some place might be flawed.
'...if only "Jumping to a Conclusion" was an event in the Olympics.'
'triprotic'??
What's that?
Watching porn on acid or something?
What they did was take samples of bacteria from the mud, and placed them in three conditions. In one condition they kept raising the cells in normal, phosphorous containing substrate, removing a small portion to another phosphorous containing substrate, and repeating for generations. In another they put the cells on a substrate lacking phosphorous or arsenic, and removed a small portion to another empty substrate, and so on. Finally, they put some on a substrate containing phosphorous and arsenic, and kept pulling out small proportions an introducing them to plates higher and higher in arsenic. The serial dilutions eventually decreased the amount of phosphorous to amounts too small to account for the needs of bacteria. Cells grew on both phosphorous and arsenic plates, but they grew better in phosphorous. The arsenic cells had some weird vacuoules which might be helping to stabilize the arsenic based compounds.
They don't know if cells in the wild have this ability or if they evolved the ability over the course of serial dilutions. A simple mass spec can tell that the ones in the wild are not mostly arsenic based though.
See, this is why I hate slashdot.
Instead of telling us 'Gizmodo was right', like we all read Gizmodo and keep constantly up to date about what's going on over there, how about TELLING US THE ACTUAL THING THAT HAPPENED.
No, I shouldn't have to follow a link to figure it...there's supposed to be an 'article summary', which, you know, gives some hint as to what happened.
Instead of just saying 'Oh, hey, these other people were right in their guess about a thing which i won't mention that they thought NASA would say.'. Well, woo-fucking-hoo. I'm sure we were all on the edge of our seat betting in the 'How correct is Gizmodo?' pool, and they just got a point! Wow! Who cares about actual news events, let's all sit there and count Gizmodo's points, or something.
Timothy, you goddamn fucking moron. It's one thing when the article summary is misleading or just flat out incorrect, but slashdot has now managed to hit a new low where the article summary doesn't even exist.
If corporations are people, aren't stockholders guilty of slavery?
This link may help. If not (it is, after all, a link to the chemistry department of a university), this, this, or this may.
And yes, since it has to do with DNA it is indeed porn on acid. Or maybe acid on porn.
Free Martian Whores!
I understand what you're saying here, but from everything we know (and we know a lot), the periodic table of elements is universal.
Some molecules (such as carbon or hydrogen) are simply so unique that they cannot be replaced by anything else. Nothing has the stability and bonding ability of carbon.
Similar things were thought about phosphate groups. Unfortunately, we were wrong.
The long and short of it is that no matter how hard you try, you'll never have an organism without hydrogen or carbon because there is simply no substitute. Same goes for a LOT of other things.
Sure, there will always be a lot of diversity and changes, but some things are simply universal.
We do have random, but it's random contained within limits set by chemistry and physics
the cell has either found a way to strengthen the backbone or has developed an amazing repair mechanism which can deal with frequent DNA damage
Hmmm. Maybe it methylates the DNA more? Or the histones are different. I guess - as you say - more repair enzymes is quite likely, since that just requires some promoter mutations.
The interesting question for me is whether any of the mechanisms are different for this organisms enzymes. For the last few months I've been sitting on the next desk to the maintainer of a database of biochemical mechanisms (MACiE - hi gemma, assuming you read slashdot, and happy birthday...) so maybe that's why it occurs to me. Many enzymes use ATP/NAD/other phosphate cofactors to make stuff, so if AsO4 has a slightly different chemistry, I wonder if different sidechains are used. Or, as I say, some completely different mechanisms (or pathways?).
I wonder if they found the Old Lace component yet.
For conscience is the wound, and there's naught to staunch it
Arsenic (As) is a poison in the same way that carbon monoxide (CO) is a poison:
CO binds to the hemoglobin molecule in the same way that oxygen (O2) does (in fact, hemoglobin favors CO quite strongly in preference to O2). The blood then starts delivering CO to the cells instead of O2. The cells need O2 to live, and they can’t use CO, so they die.
As combines chemically in many of the same ways that phosphorus (P) does (As is directly underneath P in the periodic table), and P is one of the basic building blocks of life. So it’s no surprise that the As replaced the P in the body of this bacterium. The surprise is that the bacterium apparently can live with that. Most life forms can’t; they’d die before even a small percentage of their P atoms had been displaced by As.
If I had to wager a guess, I’d say that it’s only possible because it’s such a simple life form and As apparently works just well enough for it to use it instead of P without dying. But then, I’m not a NASA scientist nor am I itching for federal funding, so I’m probably not blowing this anywhere near out of proportion enough.
For the detailed explanation of why As is toxic, I relied on Wikipedia... but basically, it replaces P, and then bad stuff happens. But Wikipedia’s explanation is not for the faint of heart:
Arsenic disrupts ATP production through several mechanisms. At the level of the citric acid cycle, arsenic inhibits lipoic acid which is a cofactor for pyruvate dehydrogenase; and by competing with phosphate it uncouples oxidative phosphorylation, thus inhibiting energy-linked reduction of NAD+, mitochondrial respiration, and ATP synthesis. Hydrogen peroxide production is also increased, which might form reactive oxygen species and oxidative stress. These metabolic interferences lead to death from multi-system organ failure, probably from necrotic cell death, not apoptosis.
Distributed Denial of APK: It takes 15 seconds to reply to him anonymously, but wastes tons of his time if we all do it.
Very interesting, but I get the impression that NASA is merely trying to demonstrate to the public why they're important and why they deserve our tax dollars. Not that they need convincing me, but they've got a lot of competition for tax money right now.
I just read that the House passed a $4.5 billion child nutrition bill apparently intended to promote better eating habits. $4.5 billion for the government to do something kids will ignore and parents should be responsible for anyway. And in the meantime NASA gets screwed.
Yes. This is pretty significant. I wonder if there are any viruses that can effect them. Read about the Hershey–Chase experiment if you want to see how significant this is https://secure.wikimedia.org/wikipedia/en/wiki/Hershey%E2%80%93Chase_experiment
Similar things were thought about phosphate groups. Unfortunately, we were wrong.
Unfortunate? I don't think it's unfortunate at all. It's things like this that make us question our "universal truths" that makes science so interesting and worthwhile.
If we already knew everything there would be no need for science. We may "know a lot", but there's not a shortage of new things to learn.
I don't necessarily think you're wrong about the carbon and hydrogen thing - I've only really studied a little physics and chemistry, no biology. But I do think you need to be more open to being wrong - and to see it as an opportunity to grow rather than as a slap in the face.
which is totally what she said
I accept your apology.
slashdot: where everyone yells sarcastic metaphors to themselves to understand the issue
I captured and converted it to mp4 format for anybody that wants to view it.
http://www.wuala.com/danathar/public
file is nasa.mp4 (it's the only one on that page)
Actually, they DID discover a new life form. They didn't actually coax an existing bacteria to "use phosphorus". Instead, they discovered an existing organism that can use arsenic in its DNA and RNA rather than the phorphorus other life on earth uses.
Free Martian Whores!
Thanks for filling in the blanks. There's some things that I deal with so often that I forget I can sound a little weird when I get excited about science and open my mouth - phosphate is one of them.
But yeah - the short story is that phosphate (and arsenate) have three spots to kick hydrogen on or off with - and the number of hydrogens that hang out on a phosphate ion is very much related to the pH.
The long story (for anyone who cares) is that each of those hydrogens has a different equilibrium constant (pKa) at which it will pop off. H3PO4 is phosphoric acid but if you increase the amount of OH- in solution (or reduce the amount of H+) the first of those hydrogens will hook up with the OH- to make water which leaves H2PO4-. So the next hydrogen to take a hike will leave the phosphate at HPO4- - which means it's harder to leave and has a different pH (which is a fancy way of talking about the levels of H+ and OH- in water) it will hit equilibrium with. So on and so forth for each of the four phosphate species (0, -1, -2, -3 charge).
The really long version throws out concentration of the different species of phosphate and talks about activities, taking into account that the activity coefficient is affected by the square of the ion's charge... [We interrupt this chemistry lesson for the sake of sanity]
Strange - I forgot what I was talking about - but back to your question: yeah - DNA is both sex and acid
Since nobody is apparently willing or able to be helpful here I'll go myself. If you're trying to play this on Debian with Iceweasel and you, like me, are being sabotaged by the NASA website's extra-dumb client detection scripts this may work for you as well.
1) Download the asx file:
$ wget http://www.nasa.gov/55644main_NASATV_Windows.asx
2) Find the playlist file link inside the text file then wget it:
$ wget http://playlist.yahoo.com/makeplaylist.dll?id=1369080&segment=149773
3) Play the resulting file directly with vlc:
$ vlc makeplaylist.dll\?id\=1369080
This worked for me. I hope it helps someone else, but really NASA should fix their shit.
DISCLAIMER - I am not an organic chemist. (although I did stay in a Holiday Inn Express last night)
Having watched the computer simulation, what I see is an organism that substitutes arsenic for phosphorus in all its internal chemistry.
Arsenic is similar enough to phosphorus, from a chemical standpoint, that the substitution works to form similar molecules - so DNA is still DNA, ATP is still ATP, etc.
In other words, this is still good old Terran life chemistry and life processes with a raw materiel switched out. It isn't an organism whose genetic material wasn't made from DNA, or whose energy source was something other than ATP.
This, to me, looks like evolution in action. An organism living in an environment short on phosphorus but long on arsenic evolved to successfully swap the one for the other - but it did it with the same building blocks.
To use a Slashdot car analogy, this is a car whose engine block and connecting rods are made of aluminum instead or iron; the parts are still the same, but the material is different. To be truly "alien" (in construction if not origin) the car would have to be powered by a turbine, or by electricity (no no engine block or connecting rods at all)
DG
Want to learn about race cars? Read my Book
What if this microbe isn't "new" - what if it is old?
As in - what if life on Terra initially evolved based around an arsenic atom, and then later evolved to use the much better and more stable phosphorus?
DG
Want to learn about race cars? Read my Book
You seek certainty. That only exists in theory. In practice, we know the laws of physics are universal, for all practical purposes, for the reasons I mentioned. If that isn't good enough for you, stick with divinity school. Science is not for you.
Edith Keeler Must Die
A "web log" is the log kept by a web server. It may also mean something else to other people, but IMNSHO that meaning is incorrect when applied in the context of a web service. And also completely irrelevant to the point I made, which doesn't depend on whether you call slashdot a 'blog', a 'discussion board', a 'masturbation aid' or even 'cheese.'
The point is the intended purpose for whatever you call this place, which isn't "unceasing gratuitous bashing of any convenient disliked target", and I'm expressing my opinion that it is disappointing and depressing to see it continue ad nauseum.