Second layer of information in DNA confirmed
Leiden theoretical physicists have proven that DNA mechanics, in addition to genetic information in DNA, determines who we are. Helmut Schiessel and his group simulated many DNA sequences and found a correlation between mechanical cues and the way DNA is folded. They have published their results in PLoS One.
When James Watson and Francis Crick identified the structure of DNA molecules in 1953, they revealed that DNA information determines who we are. The sequence of the letters G, A, T and C in the famous double helix determines what proteins are made ny our cells. If you have brown eyes, for example, this is because a series of letters in your DNA encodes for proteins that build brown eyes. Each cell contains the exact same letter sequence, and yet every organ behaves differently. How is this possible?
Mechanical cues
Since the mid 1980s, it has been hypothesized that there is a second layer of information on top of the genetic code consisting of DNA mechanical properties. Each of our cells contains two meters of DNA molecules, and these molecules need to be wrapped up tightly to fit inside a single cell. The way in which DNA is folded determines how the letters are read out, and therefore which proteins are actually made. In each organ, only relevant parts of the genetic information are read. The theory suggests that mechanical cues within the DNA structures determine how preferentially DNA folds.
Simulation
For the first time, Leiden physicist Helmut Schiessel and his research group provide strong evidence that this second layer of information indeed exists. With their computer code, they have simulated the folding of DNA strands with randomly assigned mechanical cues. It turns out that these cues indeed determine how the DNA molecule is folded into so-called nucleosomes. Schiessel found correlations between the mechanics and the actual folding structure in the genome of two organisms—baker's yeast and fission yeast. This finding reveals evolutionary changes in DNA—mutations—that have two very different effects: The letter sequence encoding for a specific protein can change, or the mechanics of the DNA structure can change, resulting in different packaging and levels of DNA accessibility, and therefore differing frequency of production of that protein.
Read more at: http://phys.org/news/2016-06-layer-dna.html#jCp
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Epigenetics is the key to why one identical twin might get cancer while the other does not. I think this discovery is epigenetics.
http://en.wikipedia.org/wiki/Epigenetics
Thanks for posting.
The thing that always amazes me is the willingness of the moron crowd to say things like "Science takes more faith than religion...to 'believe' in evolution (or climate change, or the age of the Earth, or the <insert fundie nonsense here>
for example.
I do not 'believe' in anything scientific because belief is not required! I accept theories based on evidence and I am awed by the vastness of the universe, the enormity of the variation and information and the infinitesimal nature of humanity in that scheme.
I prefer to think of 'life' (in all its general forms and in my being's specific experience of it) as one big, never ending experiment. The universe has brought the atoms which form the molecules which go on to form "me" together for this brief moment I consider "living". In less than the blink of an eye in cosmic time, the experiment that is "me" will end and be gone forever more. When these atoms and molecules cease to coalesce and drift away into other forms and other combinations, my hope is that something I experience during this interlude will go on and contribute to the ceaseless experiment of 'life'. The accumulation of excess material goods is very petty in this world view...comfort is great, but opulence is gauche and a waste of precious time...
The fact that others wish for piles of terrestrial material goods, or clouds and pearly gates and large humanoids with long white beards, or virgins and rivers of milk and honey, does not bother me - it only saddens me. The world of wonder that is beyond our current understanding is millions of times greater than the sum of our knowledge and experience to date, and adding to that insignificant total - in ANY way - would make for a better world in the end and represents a life well lived to me. YMMV!
