Prehistoric Gene Reawakened To Battle HIV 360
Linuss points out research published in PLoS Biology that demonstrates the reawakening of latent human cells' ability to manufacture an HIV defense. A group of scientists led by Nitya Venkataraman began with the knowledge that Old World monkeys have a built-in immunity to HIV: a protein that can prevent HIV from entering cell walls and starting an infection. They examined the human genome for any evidence of a latent gene that could manufacture such a protein, and found the capability in a stretch of what has been dismissively termed "junk DNA." "In this work, we reveal that, upon correction of the premature termination codon in theta-defensin pseudogenes, human myeloid cells produce cyclic, antiviral peptides (which we have termed 'retrocyclins'), indicating that the cells retain the intact machinery to make cyclic peptides. Furthermore, we exploited the ability of aminoglycoside antibiotics to read-through the premature termination codon within retrocyclin transcripts to produce functional peptides that are active against HIV-1. Given that the endogenous production of retrocyclins could also be restored in human cervicovaginal tissues, we propose that aminoglycoside-based topical microbicides might be useful in preventing sexual transmission of HIV-1."
Wow, a new approach. (Score:2, Informative)
Re:This is good news (Score:5, Informative)
If we have it, it must have evolved for a reason. Currently inactive DNA was active in the past. There's just no evolutionary pressure for it to be removed, so it sticks around.
Nope: We have a greater-than-1% difference with chimps, our closest living relatives. The Amoeba dubia [wikipedia.org] has more than 200 times the amount of DNA than humans.
Not surprised (Score:5, Informative)
It seems to me that we carry a "catalog" of genes that are not currently useful, but have been useful in the past. It's not as if evolution destroys genes - for the most part it tends to make them inactive.
Re:Old world monkey (Score:5, Informative)
Old World = Africa, Europe, Asia
New WOrld Monkeys are those found in the Americas.
Old World Monkeys are those found in Africa/Europe/Asia
Specifically, Babboons, Colobus, etc.
Old world monkeys usually have tails, but unlike the New World Monkeys, their tails are NOT prehensile (i.e. they can't use them like a tentacle).
P.S. Wikipedia is your friend.
Re:Old world monkey (Score:4, Informative)
Re:The Dilemma (Score:5, Informative)
They've finally found a use for the tail fins on a 1962 Impala. Now they're looking in junk yards to find some good copies of them and plan to weld them on to next year's Prius.
Re:The Dilemma (Score:4, Informative)
Unfortunately, Microsoft just got a patent on it.
Re:This is good news (Score:5, Informative)
If we have it, it must have evolved for a reason. Currently inactive DNA was active in the past. There's just no evolutionary pressure for it to be removed, so it sticks around.
You're sort of getting at how evolution works, but I have to nitpick your word choices. The whole idea is that evolution is random and patterns only emerge when those random mutations lead to statistically significant implications for survival and reproduction.
So it's misleading to say anything "evolved for a reason" because evolution isn't an intelligent process -- it doesn't do things because of reasons. It's also not exactly true that "[c]urrently inactive DNA was active in the past" because every generation is bound to produce lots of random genetic mutations which have no impact on our survival, in many cases because they have no impact on our physiology whatsoever. The commented (computer) code analogy is very apt here.
However, what you're hinting at isn't just that "we have it", it's more precisely that "we all have it." The fact that a large portion of the human population all has the same inactive DNA in this position does imply that it was active in the past, and that it was beneficial in the past, because that's the only way the same DNA could end up in every person's genome. If it had never been active or useful, then we would all have had to (randomly) mutate the same useless code in that spot, which would be statistically very improbable.
Re:Did anybody see Jurassic Park? Planet of the Ap (Score:5, Informative)
To dumb it down for you:
"The mumbo jumbo we did caused the cells of some female naughty parts to create some stuff that made those cells safe from HIV."
Don't feel too outclassed, they aren't getting laid either.
Not called junk DNA (Score:5, Informative)
People be careful when you summarize research in evolution. Creationists are known to quote mine and they repeatedly quote the mistaken summary (like the one posted here in slashdot) but attribute it, wrongly and knowlingly to the science article. No matter how many times you correct they continue to persist in their misrepresentation. Finding pseudogene is quite common and it actually strengthens the argument for a common ancestor. Like all mammals can make their own Vitamin C. But we primates cant. The gene to make the vitamin exists as a mutated pseudogene in our genome. Such pseudogenes are quite common.
But somehow in the mind of a creationist, gaining understanding of the original function of a pseudogene is somehow an evidence against evolution. Don't feed these trolls with sloppy summaries.
I am very sure, creationists will trumpet "Scientists have pie in their face. New function found in junk DNA. Death of Evolution is neigh. Halleluja!" quoting this very summary.
Re:The Dilemma (Score:5, Informative)
Re:Junk is not Junk (Score:4, Informative)
Junk DNA = We don't really know what it does
Not so much anymore; these days, it's more like it does not act in the simple, straightforward way that we expect genes to act. But then, genes don't seem to [harvard.edu] much, either. We're learning more and more about the many ways that "junk" DNA actually does play an active role in shaping human biology [sciencedaily.com]. (Original, more technical article [sciencemag.org].)
Re:Prehistoric Gene FTW! (Score:5, Informative)
Junk DNA is one of the greatest misnomers in genetics. It basically arose because people didn't understand the purpose of a particular gene, or they found (as in this case) that a sequence was prematurely terminated due to an encoding error, which could only be detected via comparison to another working copy from another source.
This opens up a new field of bug detection: looking for broken code, figuring out what patch is needed and then figuring out what you could do with the repaired gene. This is going to call for vast amounts of computer simulations.
In this case we were led to a solution to the breakage by a similar gene in another species. But there must be millions of broken genes laying about that might re-enable some traits, anything from gills to the ability to smell tyrannosaur breath. (Pedants: Look, its a joke, please don't bother pointing out the time line here, Ok?).
There seems a tendency to assume all "lost things", (genes, knowledge, secrets of the universe, methods of building pyramids, etc) are of immense value, and far superior to knowledge we have today. (Slashdotters will surely have a term for this.) Not everything lost is desirable. This is one example that may well be.
Many species might be expected to genetically re-energize, by natural means, any lost protection in the face of a re-appearing threat. That might take eons. If this discovery leads to a treatment, it will be signal the dawn of genetic dumpster diving on a huge scale.
Re:Prehistoric? (Score:4, Informative)
It's a bit more like putting "return;" in the middle of a function – the rest of the function is still there, but it never runs.
Re:A bit unclear to me... (Score:3, Informative)
They did test the possibility of strengthening HIV. The article goes into detail about that. Short answer, it doesn't. They used a weakened concentration of the HIV killer, weakened so much it couldn't kill HIV, and ran a constant stream of HIV past it, then examined the results. There were no changes.
That makes a certain amount of sense because of how it works. It's not an HIV killer as in "attacks and dismantles the virus." It's an HIV killer in that it prevents the virus from successfully replicating. It binds to HIV precursor material in places that prevents the different precursor materials from successfully joining up into a fully formed virus. At sufficient concentrations (which aren't very high at all, judging by the regular use of the micrograms per milliliter measurement unit that shows up in the article), it interferes with basically all HIV replication. You can't breed an evolved, stronger form of the virus if there are no new generations of the virus. With this treatment, there are no survivors.
Re:A bit unclear to me... (Score:3, Informative)
Unfortunately no. They're not actually changing the DNA. The cream/lotion concept (which they don't actually have yet) would contain the special molecule they tested that is built to help a cell read past the premature terminator in the gene sequence, so it can successfully build the proteins we're talking about. It's hitting the Retry button on the Abort, Retry, Fail prompt and successfully getting past the bad sector. But it's a local, temporary thing.
In theory, yes, a retrovirus could be engineered to actually remove the bad sector, in every cell everywhere, in all people. That's not what they're talking about here though. DNA modification seems to be a good deal trickier than providing an error correction reader molecule.
Nethack (Score:1, Informative)
I know that bones files can be annoying, but a wand of cancellation or a blessed scroll of remove curse can take care of that right quick.
Also, if you're smart enough to keep everything in bags, only the bag will end up cursed (though you definitely have to uncurse a bag of holding before you loot it!)
HIV immunity (Score:3, Informative)
There are reports of some women in Africa that are immune to HIV.
Years ago there was an article linked to on Slashdot about some women prostitutes in Africa who were immune. I tried to find it but perhaps I didn't spend enough tyme because I didn't find it. A few days ago I found another one where some women in China appeared to be immune as well. Here's "Two women found with HIV-immune mutant gene [chinadaily.com.cn]".
Falcon