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Extra letters added to life's genetic code

Scientists have created bacteria that thrive using an expanded "genetic alphabet".
The blueprint for all life forms on Earth is written in a code consisting of four "letters": A, T, C and G, which pair up in the DNA double helix.
But the lab organism has been modified to use an additional two, giving it a genetic code of six letters.
Researchers hope the work could lead to bugs that can help manufacture new classes of drugs to treat disease.
 
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DNA could have existed long before life itself

Chemists are close to demonstrating that the building blocks of DNA can form spontaneously from chemicals thought to be present on the primordial Earth. If they succeed, their work would suggest that DNA could have predated the birth of life.
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"New" Genes May Have Played a Role in Human Brain Evolution

Billions of years ago, organic chemicals in the primordial soup somehow organised themselves into the first organisms. A few years ago scientists found that something similar happens every once in awhile in the cells of all living things: bits of once-quiet stretches of  DNA sometimes spontaneously assemble themselves into genes. Such "de novo" genes may go on to play significant roles in the evolution of individual organisms - even humans. But how many are there?
More than anyone thought, it turns out.

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DNA sequenced of woman who lived to 115

The entire DNA sequence of a woman who lived to 115 has been pieced together by scientists.
The woman, who was the oldest in the world at the time of her death, had the mind of someone decades younger and no signs of dementia, say Dutch experts.

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UNC researchers identify seventh and eighth bases of DNA

For decades, scientists have known that DNA consists of four basic units -- adenine, guanine, thymine and cytosine. Those four bases have been taught in science textbooks and have formed the basis of the growing knowledge regarding how genes code for life. Yet in recent history, scientists have expanded that list from four to six.
Now, with a finding published online in the July 21, 2011, issue of the journal Science, researchers from the UNC School of Medicine have discovered the seventh and eighth bases of DNA. The findings shed new light on one of the most important molecules in the evolution of life on Earth.
These last two bases - called 5-formylcytosine and 5 carboxylcytosine - are actually versions of cytosine that have been modified by Tet proteins, molecular entities thought to play a role in DNA demethylation and stem cell reprogramming.

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Chemische Evolution eines Bakteriengenoms gelungen

Einem internationalen Team von Forschern mit Beteiligung der Freien Universität Berlin ist es gelungen, ein Bakterium zu erzeugen, in dessen Erbinformation ein Baustein durch ein synthetisches Element ausgetauscht ist. Die Ergebnisse wurden unter dem Titel "Chemical Evolution of a Bacterium's Genome" in der jüngsten Ausgabe des Fachmagazins "Angewandte Chemie - International Edition" veröffentlicht. Bei dem ausgetauschten Baustein handelt es sich um eine der vier Basen, aus denen die Trägerin der Erbinformation aller lebenden Zellen kodiert ist, die Desoxyribonukleinsäure (DNS). Die Wissenschaftler erzeugten ein Bakterium, bei dem die drei Basen Adenin (A), Cytosin (C) und Guanin (G) erhalten blieben, der vierte Baustein Thymin (T)  jedoch durch einen synthetischen, für andere Organismen giftigen Baustein, 5-Chloruracil ausgetauscht wurde.
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The "Molecular structure of Nucleic Acids: A Structure for Deoxyribose Nucleic Acid" was an article published by James D. Watson and Francis Crick in the scientific journal Nature in its 171st volume on pages 737738 (dated April 25, 1953)
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Double Helix - The DNA Years



Double Helix - The DNA Years 1 of 12 - BBC Science and History Documentary

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Bat and dolphin DNA

Scientists have found a striking similarity in the DNA that enables some bats and dolphins to echolocate.
A key gene that gives their ears the ability to detect high-frequency sound has undergone the exact same changes over time in both creatures.
The researchers report their findings in the journal Current Biology.

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Small stretches of seemingly useless DNA harbour a big secret, say researchers at the Stanford University School of Medicine. There's one problem: We don't know what it is. Although individual laboratory animals appear to live happily when these genetic ciphers are deleted, these snippets have been highly conserved throughout evolution.

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