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Originally posted by Science Daily
Scientists create first living organism that transmits added letters in DNA 'alphabet'
Scientists at The Scripps Research Institute (TSRI) have engineered a bacterium whose genetic material includes an added pair of DNA "letters," or bases, not found in nature. The cells of this unique bacterium can replicate the unnatural DNA bases more or less normally, for as long as the molecular building blocks are supplied.
"Life on Earth in all its diversity is encoded by only two pairs of DNA bases, A-T and C-G, and what we've made is an organism that stably contains those two plus a third, unnatural pair of bases," said TSRI Associate Professor Floyd E. Romesberg, who led the research team. "This shows that other solutions to storing information are possible and, of course, takes us closer to an expanded-DNA biology that will have many exciting applications -- from new medicines to new kinds of nanotechnology."
The report on the achievement appears May 7, 2014, in an advance online publication of the journal Nature.
Many Challenges
Romesberg and his laboratory have been working since the late 1990s to find pairs of molecules that could serve as new, functional DNA bases -- and, in principle, could code for proteins and organisms that have never existed before.
The task hasn't been a simple one. Any functional new pair of DNA bases would have to bind with an affinity comparable to that of the natural nucleoside base-pairs adenine-thymine and cytosine-guanine. Such new bases also would have to line up stably alongside the natural bases in a zipper-like stretch of DNA. They would be required to unzip and re-zip smoothly when worked on by natural polymerase enzymes during DNA replication and transcription into RNA. And somehow these nucleoside interlopers would have to avoid being attacked and removed by natural DNA-repair mechanisms.
Despite these challenges, by 2008 Romesberg and his colleagues had taken a big step towards this goal; in a study published that year, they identified sets of nucleoside molecules that can hook up across a double-strand of DNA almost as snugly as natural base pairs and showed that DNA containing these unnatural base pairs can replicate in the presence of the right enzymes. In a study that came out the following year, the researchers were able to find enzymes that transcribe this semi-synthetic DNA into RNA.
But this work was conducted in the simplified milieu of a test tube. "These unnatural base pairs have worked beautifully in vitro, but the big challenge has been to get them working in the much more complex environment of a living cell," said Denis A. Malyshev, a member of the Romesberg laboratory who was lead author of the new report.
Scientists at The Scripps Research Institute (TSRI) have engineered a bacterium whose genetic material includes an added pair of DNA "letters," or bases, not found in nature. The cells of this unique bacterium can replicate the unnatural DNA bases more or less normally, for as long as the molecular building blocks are supplied.
"Life on Earth in all its diversity is encoded by only two pairs of DNA bases, A-T and C-G, and what we've made is an organism that stably contains those two plus a third, unnatural pair of bases," said TSRI Associate Professor Floyd E. Romesberg, who led the research team. "This shows that other solutions to storing information are possible and, of course, takes us closer to an expanded-DNA biology that will have many exciting applications -- from new medicines to new kinds of nanotechnology."
The report on the achievement appears May 7, 2014, in an advance online publication of the journal Nature.
Many Challenges
Romesberg and his laboratory have been working since the late 1990s to find pairs of molecules that could serve as new, functional DNA bases -- and, in principle, could code for proteins and organisms that have never existed before.
The task hasn't been a simple one. Any functional new pair of DNA bases would have to bind with an affinity comparable to that of the natural nucleoside base-pairs adenine-thymine and cytosine-guanine. Such new bases also would have to line up stably alongside the natural bases in a zipper-like stretch of DNA. They would be required to unzip and re-zip smoothly when worked on by natural polymerase enzymes during DNA replication and transcription into RNA. And somehow these nucleoside interlopers would have to avoid being attacked and removed by natural DNA-repair mechanisms.
Despite these challenges, by 2008 Romesberg and his colleagues had taken a big step towards this goal; in a study published that year, they identified sets of nucleoside molecules that can hook up across a double-strand of DNA almost as snugly as natural base pairs and showed that DNA containing these unnatural base pairs can replicate in the presence of the right enzymes. In a study that came out the following year, the researchers were able to find enzymes that transcribe this semi-synthetic DNA into RNA.
But this work was conducted in the simplified milieu of a test tube. "These unnatural base pairs have worked beautifully in vitro, but the big challenge has been to get them working in the much more complex environment of a living cell," said Denis A. Malyshev, a member of the Romesberg laboratory who was lead author of the new report.
http://www.sciencedaily.com/releases...cienceDaily%29
Wow, an organism with different DNA to anything else on earth. That's some amazing work. Surely someone just earned themselves a Nobel?
) has different DNA to anyting else on earth 
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