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Genome of Controversial Arsenic Bacterium Sequenced
Med-trump writes "One year ago a media controversy was ignited when Felisa Wolfe-Simon and her colleagues held a press conference to announce the discovery of a bacterium that not only survived high levels of arsenic in its environment but also seemed to use that element in its DNA. Last week, the genome of the bacterium, known as GFAJ-1, which gets its name from the acronym for 'Give Felisa a Job.' (No joke!), was posted in Genbank, the public repository of DNA sequences for all who care to take a look. But it doesn't settle the debate over whether arsenic is used in DNA."
Not enough in this case.
They know that this bacteria lives in an environment of Arsenic and may use it in its cell process. So any Spectrometric study will show Arsenic as contamination. Even if you clean up for that, there might be bits of Arsenic stuck in the DNA, but which do not do anything. I believe what they are trying to do is to see if Arsenic is a "functional" part of DNA. ie would the DNA without Arsenic be the same as arsenic without it.
http://slashdot.org/submission/1062723/Cheap-mobile-data-plan?art_pos=2
Anything that involves Drosophila in gerneral and especially Christiane Nüsslein Vollhard is just plain silly....
examples (along with the translation if necessary)
Spätzle (a swabian kind of noodle), wingless, toll (either great or crazy), Gurke (cucumber), tube, Pelle (husk/peel), Krüppel (cripple) etc....
Basically they tried to destroy/deactivate/mutate random genes necessary for the development of the fly, without knowing what they'd hit. Then they looked for larvae or flies that looked weird or behaved funky and named them with whatever they associated with it. Finally they took the animal and tried to find the gene they deactivated. If successful, they'd give that original name to the gene, no matter how stupid the name was and no matter how important the gene is. Hilarity ensued.
Mass spectrometry using ESI ionisation should be able to detect DNA bases with arsenium replacing phosphor in the 5' phosphoester bound to ribose. It should be trivial to distinguish free arsenic from incorporated arsenic.
The counterpoint of this is that if *everyone* assumed someone smarter than them was already "on it", then the forward progress of our society would grind to a halt.
Calling someone out on it is counter productive because it discourages asking questions, thus making you simply a troll.
Science is all about asking questions. In fact I learned something because of their question. It is something that had I thought about it I likely could have come up with the answer, but having it elucidated for me was helpful, and that was about not being able to tell (and ways you could possibly tell) whether the arsenic was merely sticking to the DNA strand, or if it was actually in place of the phosphorous.
Remember the greatest discoveries are not usually preceded by "eureka!", but rahter "hmmm... that's funny".
-nB
whois gawk date unzip strip find touch finger mount join nice man top fsck grep eject more yes exit umount sleep dump
The paper was fine. Her handling of some of the samples may not have been what one would want.
The sensationalism is the problem. Her conclusion, while unexpected and quite possible wrong, are fine based on the experiment.
This will be worked out like science is worked out. People will try to recreate it, and the DNA will be put under a Mass Spec.
All of which is in the article.
Shit. I just realized you posted AC. So, you are crap. Normally I don't bother with AC, but since I wrote it, I'll post it.
The Kruger Dunning explains most post on
They know that this bacteria lives in an environment of Arsenic and may use it in its cell process. So any Spectrometric study will show Arsenic as contamination.
What matters is whether the arsenic is covalently bound to functional groups like adenosine, which mass spectrometry is able to detect.
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