Science

Scientists confirm DNA holds a second layer of information

Scientists confirm DNA holds a...
Physicists at Leiden Institute of Physics have confirmed a long-standing hypothesis, that a second layer of information exists on top of the genetic code in DNA
Physicists at Leiden Institute of Physics have confirmed a long-standing hypothesis, that a second layer of information exists on top of the genetic code in DNA
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Physicists at Leiden Institute of Physics have confirmed a long-standing hypothesis, that a second layer of information exists on top of the genetic code in DNA
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Physicists at Leiden Institute of Physics have confirmed a long-standing hypothesis, that a second layer of information exists on top of the genetic code in DNA

Everything that makes you you is in your DNA, but a long-time hypothesis suggests that you're not just a product of the genetic code itself, but also the mechanical cues that determine how that information folds up inside your cells. Now, theoretical physicists in the Netherlands have confirmed that this second layer of information does indeed exist.

Proteins are the building blocks of our body, and through the sequence of the four main nitrogen-containing nucleobases, G, A, T and C, in our genetic code, our DNA dictates which proteins are made in the body and in what numbers. But despite the fact every cell in our bodies contains the same DNA sequence, different organs result, suggesting there is some other process at work.

Our DNA is packed into our cells extremely tightly – unravelled, the DNA molecules in each individual cell in our body stretch to about two meters (6.5 ft). One theory, dating back to the 80s, suggested that DNA's mechanical properties dictate how the strand folds up within the cell, and as a result, changes how the genetic code is read out and provides an additional layer of information on top of the sequence of G, A, T and C nucleobases in DNA's double helix structure.

A research team, led by Helmut Schiessel at the Leiden Institute of Physics, ran computer simulations to test this hypothesis and found strong evidence to suggest that these mechanical cues do in fact exist. To do so, the scientists assigned randomized mechanical cues to strands of DNA in two organisms – baker's yeast and fission yeast – and found that the DNA molecules did fold up in different ways, accordingly.

With these results, the team explains that mutations in DNA has the potential to change two different things: a specific protein's genetic letter sequence, or the DNA's mechanical structure, which will have run-on effects in how the genetic code is read out and the type and amount of proteins that are produced.

The findings were published in the journal PLOS One.

Source: Leiden Institute of Physics

15 comments
NobleButterfly
"""But despite the fact every cell in our bodies contains the same DNA sequence, different organs result, suggesting there is some other process at work.""" While I don't diseagre with the article I diseagre with the logic of this statement. This suggest nothing. One part of the DNA could be use to make an organ and an other part used to make an other organ, while still storing the entire DNA everywhere.
Robert Walther
A second layer and a third and a fourth...The levels of life are unending.
MBadgero
DNA almost certainly contains De Bruijn sequences also. It is unlikely that nature would miss such a simple trick.
FábioAlvesCorrêa
Can that means the "junk DNA" may have a more important role than previously thought?
RangerJones
De Bruijn sequences in assembly computation. Agree with NobleButterfly. Have a really hard time agreeing with the 'folding' of the strands being "mechanically cued" in two mediums and from the "folds" creating such a different genetic letter sequence of a specific protein. "Scientists confirm DNA holds a second layer of information", Not empirically true--Maybe, 'Scientists suggest'. I don't consider this "confirmation".
Andrew Keim
I agree, there has to be more layers, we have yet to discover them, but we will eventually.
Walt Stawicki
which has come first, the cell and infoldment of the mating of his and hers contributions? the point is how does the initial fold code get there through this process? how does this work at the morphology level? I'm still stuck with Alan Turing on that. If any one can integrate this with his theoretical math proposition and the body of work that somewhat follows in line...?
chris2244
An old 'discovery', like many others in the science. Please read about it in the book from Steven Druker: "Altered Genes, Twisted Truth: How the Venture to Genetically Engineer Our Food Has Subverted Science, Corrupted Government, and Systematically Deceived the Public". He explains it extremely good, especially as a public interest attorney! P. 491 with citations mentioning the relevant resources, one of them, Weatheritt's article in Science 13:342 (6164), 2013. Title of this article: "The Hidden Codes that Shape Protein evolution."
CarrieErbagSmith
I'm not a scientist, and this may be a ridiculous question - but might this finding explain why identical twins nevertheless are not exact replicas of each other? One may develop a form of cancer, the other will not. As they grow into adults, physical differences - although often small - also develop. Obviously the DNA code in itself doesn't explain everything.
Daishi
Great job to these 5 men from the Netherlands on a major scientific breakthrough.