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Prehistoric Gene Reawakened To Battle HIV
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."
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 has more than 200 times the amount of DNA than humans.
If you reply, do so only to what I explicitly wrote. If I didn't write it, don't assume or infer it.
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.
Last post!
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.
excitingthingstodo.blogspot.com
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.
Faster! Faster! Faster would be better!
I didn't understand it but it was the only word I was interested in enough to google.
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.
Sig Battery depleted. Reverting to safe mode.