Central Dogma of Genetics May Not Be So Central

Amorymeltzer writes "RNA molecules aren't always faithful reproductions of the genetic instructions contained within DNA, a new study shows (abstract). The finding seems to violate a tenet of genetics so fundamental that scientists call it the central dogma: DNA letters encode information, and RNA is made in DNA's likeness. The RNA then serves as a template to build proteins. But a study of RNA in white blood cells from 27 different people shows that, on average, each person has nearly 4,000 genes in which the RNA copies contain misspellings not found in DNA."

Central Dogma?

[Microlith]

Who do you think they are, Soulskill, NERV?

Also, science holds no dogma. If it does, it ceases to be science.

Conservative subs or not?

[RobinEggs]

The summary and the abstract really say almost nothing other than to confirm that the misspellings aren't random and don't seem like lab artifacts.

I'd be interested to know how conservative these mistakes tend to be. If the mistakes generally replace amino acids with very similar ones it might be a programmed method of prodding just how much variation a structure can take while remaining functional. Weird and random events, which can be only so weird and so frequent before everything breaks entirely, are necessary for evolutionary adaptation, and these weird protein errors might be a previously unknown mechanism of exploring slightly different structures for proteins and seeing how far an organism can push the envelope.

No Surprise

[flyingkillerrobots]

Any engineer should find this to be perfectly intuitive. When the DNA itself replicates to produce a new cell entirely, there are a lot of extra safeguards to ensure as near-exact copying as possible, as mutations can easily be fatal. For RNA copying, there is no need for this sort of precision, because even if the resulting protein is useless, the cell remains alive, and a new RNA strand can easily be produced if needed.

Central Dogma Barking Up Wrong Tree

[ColdWetDog]

(I so wanted to start the post that way)

No, the big thing about this (if indeed it holds up) is that the fidelity is much, much lower than expected. It doesn't seem that the mRNAs are miscoding (although it's possible) it seems that the coding is being jiggered with by other factors.

However, this is a statistical analysis of a number of genomes and the original genome coding teams warns that the precision of the decode may not be enough to warrant TFA's (tentative) conclusion.

But it's interesting and exciting. Stay tuned. Beats politics.

Re:Why is this news?

[RobinEggs]

That people have discovered that the intermediate step is also adjusted can hardly be called a shock.

Yes, it is a shock. The prevailing thought was that the RNA was transcribed faithfully and then that perfect transcript of the DNA was sliced up in strange ways. These people have discovered that the transcript may never have been perfect at all.

Imagine cutting up a loaf of bread: The geneticists were quibbling about how thick the slices were and how to arrange it on the plate, all without paying attention to what kind of bread they used. Now suddenly they've noticed that the recipe for french bread gave them a sourdough loaf while they aren't looking, and it may not be about the slicing as much as about how the right recipe is giving them the wrong thing to cut up.

Re:NEWS FLASH

[canajin56]

Yes, just random mistakes is why 10,000 "accidents" happen to the same exact gene exactly the same way in exactly the same spot every time, 100% of the time, in every cell their bodies, for multiple individuals. Random transcription error. Yes, you sure thought that one through. How embarrassing. No, but seriously, too bad you weren't on the peer review for the paper. You could have saved them from publishing such garbage!

Re:RTFA, the errors weren't random.

[PCM2]

That's kind of interesting, but not really amazing. Something must be causing the "mistakes" no matter how "random" they appear to be -- whether it's a virus, a stray cosmic ray or something else. The fact that it seems much less random than you'd expect just points to the likelihood that we'll soon get to the bottom of the phenomenon.

Re:Why is this news?

[jd]

Now that is very different. Not knowing why is indeed very interesting. The consequence of the misspellings depends on whether they ARE true misspellings versus data-driven modifications from non-encoding genetic material. If they are deliberate transforms, then to call them misspellings is flawed, since the spelling would then be precisely what the DNA coded for (when considering all other types of data). Likewise, when U is used in RNA, it is not considered a mis-spelling, even though that would not be the nucleotide in the DNA.

Now, there may well be consequences for non-encoded mis-spellings, and the consequences of those would be extremely interesting.

This, really, is where the interest should be.

Re:Central Dogma Barking Up Wrong Tree

[afidel]

It doesn't really matter though does it, as long as the transcription errors don't produce toxic analogs of the protein that's being encoded then the body just produces more copies of the protein until it has enough working copies. Yes, it has to expend more energy on creating and destroying the transcription errors but I would venture that this is already accounted for in the cells energy intake since it's probably been with us for a very, very long time =)

Re:This is NOT what the central dogma says

[afidel]

Except for protein encoded viruses of course which rewrite RNA and sometimes DNA =)

Re:Central Dogma?

[colinrichardday]

More like a dogma that the philosophy of science holds.

Re:Central Dogma?

[digitig]

No, it's not that. The philosophy of science doesn't hold dogmas, it identifies dogmas. Such as the metaphysical dogma of materialism. All attempts so far to eliminate that dogma from science have failed, and it doesn't look likely that it will ever be eliminated.