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New Code Discovered in DNA?
Posted by
Zonk
on Tue Jul 25, 2006 12:02 PM
from the we-needed-more-than-one dept.
from the we-needed-more-than-one dept.
anthemaniac writes "The NY Times is reporting that scientists have found a second code in DNA that goes beyond the genes. The code is superimposed genetic information and 'sets the placement of the nucleosomes, miniature protein spools around which the DNA is looped. The spools both protect and control access to the DNA itself. The discovery, if confirmed, could open new insights into the higher order control of the genes, like the critical but still mysterious process by which each type of human cell is allowed to activate the genes it needs but cannot access the genes used by other types of cell.'"
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So wait (Score:5, Funny)
So my body has built in DRM?!
Re:So wait (Score:4, Funny)
Tom
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Re:Yes, and (Score:5, Funny)
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Re:Precisely. (Score:5, Funny)
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Re:So wait (Score:5, Funny)
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Re:So wait (Score:4, Funny)
I think you mean to say, "Where the hell is God going to find a lawyer?"
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Genes, introns and nucleosomes (Score:5, Funny)
An important reminder (Score:4, Insightful)
Some of this isn't terribly new (Score:4, Interesting)
It turns out there's some vastly complex actions around how genes are actually expressed. Methylization semi-permanently deactivates DNA. Other things control the unfolding of DNA so that they're accessible to be exposed. Much of the "junk dna" is probably not junk, but rather controls gene expression to some degree.
The bottom line is that DNA is only the bottom rung of how information is stored and manipulated in the nifty little computers that are our cells. This is also a great context to talk about evolution - no sane intelligent designer would make a cell this way. If you think about small changes over billions of years, though, you can see how the warping and twisting of DNA could produce interesting results that are passed down from generation to generation.
Science is rarely boring.
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Proff of intellijent design!!!11 (Score:4, Funny)
Re:Random error produces error control mechanism? (Score:5, Insightful)
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Re:Random error produces error control mechanism? (Score:5, Interesting)
Here is some information [wikipedia.org] about reverse transcriptase error rates. In contrast, here is some [jbc.org] for one of the DNApolymerases. As I recall, in eukaryotes there are three DNA polymerases, and only DNApolyIII has bidirectional proofreading ability (I may be wrong) so only it can scan finished DNA, but all three can scan DNA while it's being built. In contrast, I don't believe there are any enzymes that can scan finished RNA (since it's not, to my knowledge, found double-stranded in anything we've found, and you'd have no way of determining that there was an error) so the best you can hope for is really good DNA->RNA fidelity, and as I said earlier, there's not much evolutionary pressure FOR that in the rest of nature, while there's some evolutionary pressure AGAINST it (because it's expensive) so if it were to exist, it would only exist in things that would benefit from it, those being small RNA viruses that are much less likely to have either the history, the machinery, or the overhead to afford proofreading replication enzymes. Besides which, if their gain (number of viruses produced for each cell infected) is high enough, they A: don't care about individual viral particle loss from bad fidelity, and B: actually benefit from high mutation rate because of its help in evading host response.
whew. that was wordy. sorry.
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Re:Random error produces error control mechanism? (Score:5, Insightful)
No, error correction would counter the mutation process. Given that, generally, more mutations are harmful than beneficial, error-correcting genetics would be a short-term benefit in reducing genetic disorders. The downside would come if another species with a higher mutation rate evolves into a more successful form and crowds out the now-obsolete organism with rigid genetics. The overall winners would likely be organisms within some range of error-correction--neither a total free-for-all, nor a very rigid genome. This seems pretty well reflected in real life, unsurprisingly.
Yes, this discovery does not hurt the ID movement at all.
This is also true; no scientific discovery will hurt the ID movement, since it has precisely nothing to do with science...
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software problem (Score:5, Funny)
So apparenlty we are a software problem.
C'mon baby... (Score:5, Funny)
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Re:C'mon baby... (Score:5, Funny)
Just don't expect you to maintain it.
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Evolution proves totally brilliant once again (Score:5, Insightful)
It's not like nucleosomes are anything new though, the real discovery here is that the scientists found a pattern to their binding.
Sadly the times article is filled with a lot of fluff. This isn't really a "second code" nor do I see why it's "hidden".
Original article (Score:5, Informative)
Metadata (Score:5, Insightful)
New Code Discovered in DNA (Score:5, Funny)
b-e-s-u-r-e-t-o-d-r-i-n-k-y-o-u-r-o-v-a-l-t-i-n-e
God-in-the-Gaps (Score:5, Insightful)
A new "twist" in an OLD OLD story... (Score:5, Informative)
FTA: "Biologists have suspected for years that some positions on the DNA, notably those where it bends most easily, might be more favorable for nucleosomes than others, but no overall pattern was apparent. Drs. Segal and Widom analyzed the sequence at some 200 sites in the yeast genome where nucleosomes are known to bind, and discovered that there is indeed a hidden pattern."
Honestly, many of us biologists are kind of giggling at how the NYT (and I guess Slashdot) have been hoodwinked by hot headlines. We have known for decades that histones bind DNA and organize it (into nucleosomes), periodically, all along its length. Now, this group has identified some concensus sequences where the nucleosomes are most likely to form. Turns out, yeah, it's what we thought, with the little twist that precise positioning of nucleosomes could help regulate gene expression (also heavily predicted and fully expected). There are new articles about DNA organization weekly. I think the NYT just picked one and labeled it as a "code beyond genetics", which is absurd, since the organization of DNA is controlled ultimately by DNA sequences. Also, if you want to talk about codes beyond genetics, there is a whole field of study called "epigenetics" [wikipedia.org], which is "the study of reversible heritable changes in gene function that occur without a change in the sequence of nuclear DNA".
Re:First DNA virus hackers? (Score:4, Insightful)
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Re:New Discovery (Score:4, Insightful)
The headline however, is unnecessarily sensationalist..
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Re:Midichlorians? (Score:4, Informative)
No, we already knew about those. They're called mitochondria, they provide the energy that powers the machinery of our cells, and they're descended from independent microscopic life forms that long ago entered a symbiotic relationship with animals.
In plants, chloroplasts fill a similar role.
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