Scientists Discover How DNA Is Folded Within the Nucleus 152
mikael writes "Sciencedaily.com is reporting that scientists have discovered how DNA is folded within the nucleus of a cell such that active genes remain accessible without becoming tangled. The first observation is that genes are actually stored in two locations. The first location acts as a cache where all active genes are kept. The second location is a denser storage area where inactive genes are kept. The second observation is that all genes are stored as fractal globules, which allows genes that are used together to be adjacent to each other when folded, even though they may be far apart when unfolded."
Hilbert Curve (Score:3, Interesting)
So.... (Score:3, Interesting)
Re:tell me something a child couldn't figure out (Score:4, Interesting)
Yeah now. Seriously, while your answer is a bit flip, I did have that thought as well. All I know about DNA is the usual buzzword stuff - double helix, Crick and Watson, ACGT... etc. I never really thought about what it actually might look like.
But the diagram showing the tangled mess vs the "fractal" folding evoked a "duh" from me as well.
The trick is to be the first to prove a non-trivial "duh" fact.
Re:So.... (Score:4, Interesting)
And it makes use of a primary cache. "That's hot."
Re:Fascinating (Score:3, Interesting)
Except that it isn't all junk. Yes there are vestigial genes and repeats such as Ala however, that does not mean that it serves no structural role. Some repeats especially GGG can distort the DNA coiling structure from the normal B form to other forms that are less useful (eg. Z).
What about beads on a string? (Score:4, Interesting)
I'm confused, here. I'm certainly no biology expert, but I have taken a few courses, one of which the prof seemed to describe exactly how DNA folds. Indeed, it's spelled out in detail on this Wikipedia page on chromatin [wikipedia.org].
Is this information now obsolete?
Re:Fascinating (Score:3, Interesting)
I don't mean that they are only vestigial and serve no structural purpose.
But rather that if they were placed there deliberately for structural purpose only it would be obvious and they would be made of vestigial genes.
They are junk, not "junk".
Re:Fascinating (Score:2, Interesting)
I do, junk DNA, as well as other minerals and enzymes and pretty much anything that floats into the cytoplasm affects the functioning of DNA, they are as much part of your genotype as anything else, as should be expected, because the parts are there and interact, so the interaction must play a role in the expression of the phenotype.
Two thins are I know are, it wasn't placed there deliberately by some supernatural entity, it does not look even remotely designed, in fact we know exactly what it looks like, vestigial genes. Also while it might be true that a single base pair repeated over and over as I suggested could not be viable, simpler arrangements should be possible and indeed, we have deleted sections of it in flies and bacteria without noticeable effects.
I'm not against or in pro of the term junk DNA, what bugs me is the scare quotes, the haha "junk" DNA is not junk after all take that science! stance of the ID drones.
Re:tell me something a child couldn't figure out (Score:2, Interesting)
The first observation is that genes are actually stored in two locations.
This threw me off at first. It read like active genes have a backup stored somewhere in the inactive part. That is not the case =). We're not having and L1/2/3 cache in our genome.
Re:Fascinating (Score:3, Interesting)
The idea of "junk DNA" is waaayyy outdated. At least by a decade! It was the old error of arrogance, that led some scientists to believe, that when they could not find a use for it, it must be "junk". Until someone found it to be in heavy use, defining the details of what you become. (There was a very interesting article in the German version of the Scientific American [called "Spektrum der Wissenschaft"] about it, some years ago.)
It's what also caused people to believe that the spleen (the standing army headquarters of the immune system, among other things) or the tonsils (many functions, also much of the immune system) would not be needed, despite them otherwise being long be gone, and not using resources anymore.
Just as, if your doctor has never seen what you have, has no idea how to heal or just treat it, etc, he will never admit that, but instead say, that there is no cure and there never will be, or even that you aren't sick at all. Even if you go and prove him wrong. Him being wrong is not in his vocabulary of things he can even think about.
And just as, right now, "scientists" state, that because they are unable to get their calculations to match real measured values, that the universe must be wrong. (Nooo, never them!) And that it hides things from us in the form of "teh ebil dark matterzorz n dark enegiez"! ^^
Re:Fascinating (Score:3, Interesting)
I didn't see one scrap of "ID drone" in the OP. I saw someone who showed a surprising amount of open-mindedness and insight for someone carrying around a 30 year old misconception about seemingly unused section of DNA. The "scare quotes" were to imply that what we call "junk" wasn't "junk." Which of course is true even if he didn't know it. It's a tremendous and unjustified leap to go from that to assuming he's say "HAHA GOD DID IT EAT THAT SCIENCE." Do you assume that someone is anti-science any time they speculate about science?
And then you appeared to reinforce that 30-year-old misconception. And still seem to. It's not all vestigial. Much of what was once thought to be vestigial actually serves important purposes in the expression of other genes. Lots of things can be deleted, even actively expressed genes, without noticeable effect. It doesn't mean they aren't having one. Simpler structures absolutely could be possible, but nature does not always opt for "simplest".