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back to article Missing DNA fails to kill mice

DNA sequences we share with mice might not be as important as researchers previously thought. A series of experiments on mice at Berkeley have cast doubt on the notion that these so-called ultraconserved elements of DNA are indispensable, after test mice with sequences snipped out managed to grow up just fine. Ultraconserved …

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So long and thanks for...

"Nadav Ahituv of Berkeley Lab's Genomics Division, a human geneticist who led the experiment, said that the results were a complete surprise."

Of course they can only name the "human geneticist" involved! Stating the name of the head mice would probably jeopardize their (the mices') project of the supercomputer EARTH.

42 all the way!

(Yes, it's Friday...)

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Mighty Mice?

Perhaps these removed DNA sequenes were inhibitors and these mice are now 'superheros' with the ability to fly, regenerate or pass through solid objects. Save Mini the cheerleader mouse, save the world.

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Anonymous Coward

The researchers are not entirely sure

quote:

"The sections are exactly alike, meaning that they are inherited from our last common ancestor over 85m years ago, and have been conserved since then without mutation."

"The biggest question the research raises is that of how these sections of DNA came to be perfectly preserved, if they are not vital to the viability of the animal? The researchers are not entirely sure."

/quote

Here's a clue, maybe it hasn't been 85m years since they were "inherited from our last common ancestor", maybe they weren't inherited at all, maybe they were just designed that way.

ROFL

Martin

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redundancies and old functionality in the code

500 million years in development, so it's about time someone cleaned up the source code.

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Copyright

I have claimed exclusive copyright on all "Ultranconserved DNA segments" and have a patent pending. All future copying will be strictly prohibited unless you pay me a license fee for each and every living creature on Earth. If you fail to pay this license and make unauthorised copies then I plan on suing every infringement. So I shall see your children, and every offspring off every living creature on Earth. See you ALL in court.

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@William

Do I need to get licenses on cell basis, or can I get a site license for my whole body. How do you manage cell exchange. Plese provide pricing ASAP as I do not wish my body to be targetted by a takedown request from the HIAA.

Not that I really care due to my current location, but well, one never know where one ends up.

In the first case, I'll make sure to return you every single cell epelled form my body in any form as to not let licence renewal fees grow too fast.

Best regards :)

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Anonymous Coward

Title

Perhaps these bits of DNA are conserved under instruction from another bit of DNA and they prevent certain diseases that those mice have not been exposed to.

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These mice must be contained!

By removing the ultraconserved elements these mice will be defenseless against the effects of ultraliberalized elements. The potentially horrendous effects of this heinous genetic manipulation on mouse society is without bounds. Even worse is the prospect of these elements (or lack thereof) becoming infiltrated into the human genome.

These mad scientists and their unholy creations must be stopped at all costs.

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Joe

reminds me of my childhood!

Reminds me of when i was a kid, i used to power up old radios and start pulling out components until they stopped working!!

sad and lonely childhood i had :(

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Leftover / junk DNA?

Has anyone taken the time to think that maybe, just maybe, that portion of the DNA simply isn't needed? It's happened before with other parts of the body. Look at the appendix -- no purpose at all. Why would it be that surprising that after so many thousands/millions of years of evolution, some of our DNA would no longer be necessary?

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Anonymous Coward

re: The researchers are not entirely sure

Is it wrong or ironic of me to want to pray that the anonymous coward (who signed his name?) is joking?

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Old news

It's obvious why it's redundant and does nothing - it's mostly comments. That was discovered for humans back in 1991.

http://www.netfunny.com/rhf/jokes/91q3/genome.html

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RE:reminds me of my childhood!

"Reminds me of when i was a kid, i used to power up old radios and start pulling out components until they stopped working!!"

You had the power to restore those old radios to working condition though. Unlike the ones who pulled components off of flies and such.

I did the same thing with my family's first color TV. My Mother caught me at my experimenting and calmly informed me that if the TV was not working when my Dad came home from work my young life would surely come to an abrupt end. And that they were perfectly capable of creating a new child to replace me. An intensely motivating factor to become a TV repairman.

Much easier than re-attaching wings.

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J

Exactly the point...

"Has anyone taken the time to think that maybe, just maybe, that portion of the DNA simply isn't needed?"

Chris, the point you miss here is that these elements are ultraconserved. Historically, every time we see something being so conserved, it has a function. The more conserved the feature, the more important it usually is. So yes, DNA changes over time, but it changes slower the more important its function is. So the obvious expectation for ultraconserved elements (which, by the way, can also be found unchanged in fish, which parted ways with our lineage MUCH longer ago than mice did) is that they must have at least some function, and probably an important one. Or they would "decay" in time.

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E

@Exactly the point...

Historically, the theory about ultraconserved strings of DNA is about three years old, and in no way proven outside of the minds of some dogmatic people who want it to be true.

"ultraconserved" probably made a fine zinger to promote some geneticists' grant application or sell her/his book. Still, it is just an unproven theory.

The people that did this experiment kind of put the cart before the horse in their comments wrt their statement about the result, as do most of the people commenting here.

What you have here is some indication of the correctness of the theory. Nothing more or less than that.

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E

Wooly headed.

"The biggest question the research raises is that of how these sections of DNA came to be perfectly preserved, if they are not vital to the viability of the animal? The researchers are not entirely sure."

Not being vital to viability ***is not*** the criteria for natural selection. Being beneficial (conversely, detrimental) to reproduction ***is*** the criteria for natural selection. These are two different things.

Evolution says that heritable mutations that make successful reproduction more likely will tend to be preserved. It is easy to see that heritable mutations that are detrimental to successful reproduction will tend to be eliminated.

Irrelevant DNA has no reproductive effect and therefore may or may not be eliminated over time. *Whether* some irrelevant DNA persists is not governed by natural selection, is not an evolutionary process - it is just dumb chance without selection.

The DNA described has no effect... there's no reason for it to be preserved *or* for it to be bred out.

The opening quote merely demonstrates wooly-headed thinking: the common mistake that evolution has intent or style or a goal. Evolution has none of these.

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DNA code

.. is not commented..

so much for "intelligent" design

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Anonymous Coward

If scientists had girlfriends ..

"we can confidently conclude that the presence of the ultraconserved elements are not required for the viability of the organism"

And yet, if I tell my girl that an IKEA book case probably just has a few extra screws thrown in with the kit, I lose the instructions, the screw-driver and bed rights for a week!

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Anonymous Coward

Re: Wooly headed

That still does not explain why that DNA is so well conserved.

If a portion of DNA doesn't carry any information that will benefit the individual's offspring, any random changes occurring in that portion of DNA should be preserved with about the same probability as its unchanged subportions. This implies that over time a large number of such random changes should accumulate. Therefore there is indeed apparent contradiction in a "non-significant" portion of DNA being conserved very well across a huge number of generations. I don't know where the error is.

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Anonymous Coward

To E

I think that *your own" assertions seem to assume that evolution has a goal. Specifically, they seem to assume that the only random changes that occur in the DNA are those that will be beneficial to the descendance and/or those that will be detrimental to the descendance, and therefore any such changes will either be eliminated (if detrimental) or conserved for a very good reason (if beneficial), or else it won't even occur. On the contrary, precisely because random changes are blind and purposeless, they will occur all over the DNA, including in its "irrelevant" portions. Many of the changes occuring in those "irrelevant" portions have no way of being eliminated, and therefore they should accumulate over time until the whole portion of DNA becomes unrecognizable. The experiment mentioned in this article seems to contradict this conclusion.

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They can't ask the mice

They can't ask the mice how their doing how they feel or if they have some instinct lacking that isn't immediately apparent it seems pretty preliminary to make the assumption that it's not needed or if it would not show effects over several(mice hundred) generations of course if they never get old and never die unless killed then we know there may be some use in it that isn't beneficial for the individual but keeps the species viable. I hate science that makes sweeping pronouncments that aren't anything but fishing for grant money.

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Look to the past to know our path in the future.

Back-Track and linkage information stored for future generations to be able to look back and see where we were coming from.

But that's just my idea...

Martin

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Anonymous Coward

Maybe they haven't checked the right things

I suspect Pennacchio may be right.

For all they know, these genes might be crucial to certain kinds of responses in the immune system that haven't been triggered in these laboratory mice, or it may simply be a gene which makes something toxic smell unpleasant. It may be that the mice have lost their instinct to run away from a cat, or that if they could, the mice would ask the researchers why they all have double vision.

Who knows?

These mice are probably fundamentally flawed in some way that we can't see.

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E

re To E & Re: Woolyheaded

OK, I see your point. But I don't think it works both ways. That something useful would tend to be preserved with good fidelity, doesn't mean that something useless cannot be also.

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Maybe they were there in case a change was needed?

Just a thought, but maybe these "spare" DNA molecules might be there in case a change of direction is needed- for example when the human race makes itself extinct and there is a need for a new species to head the foodchain?

Maybe the appendix is there for when the human race returns to a ruminant state... you know how it is, you go through your cupboard and can't bring yourself to throw out that old waffle iron that you only used twice, after all the thing is nearly brand new.....

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All this source code

All this code and still people cannot accept that someone programmed life.

The DNA code base can produce all kinds of species. It doesn't necessarily mean that mice and man have a common ancestor as it can also mean that they were created by the same programmer who has a code base by which all living things are constructed from.

In fact we have something like 40% DNA in common with daffodils, so maybe hippies and daffodils share a common ancestor.

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Anonymous Coward

But wait....

"We fully expected to demonstrate the vital role these ultraconserved elements play by showing what happens when they are missing. Instead, our knockout mice were not only viable and fertile but showed no critical abnormalities in growth, longevity, pathology, or metabolism,"

- Yet

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Anonymous Coward

to E again

"That something useful would tend to be preserved with good fidelity, doesn't mean that something useless cannot be also"

I disagree.

A useful segment of DNA should be preserved with good fidelity because, when a change occurs in it, the whole segment may cease to be useful, and this will cause **the change** to be eliminated from the population.

A useless segment of DNA should not be preserved with good fidelity because, when a change occurs in it, nothing will cause the change to be eliminated from the population, and therefore the changes will accumulate over many generations.

Useful segments resist changes.

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