Category Archives: Transhuman News

Scientists have created the first organism with synthetic DNA that can replicate in a cell, an achievement that promises to add new letters to the genetic code underlying life on earth.

In the natural world, just two chemical base pairs, known simply as A-T and C-G, constitute the building blocks of DNA in all life forms. Research published today in the scientific journal Nature describes the creation of a cell that contains a man-made base pair, dubbed d5SICS-dNAM.

By expanding the natural boundaries of what constitutes life, scientists hope they can one day create new proteins that can handle a variety of chores in the body, potentially leading to unique ways to attack disease. The approach is safe, the researchers said, because it includes a chemical additive that the cell needs to survive.

We created an organism that lives and stably harbors genetic information in its DNA, said Floyd Romesberg, a chemist at La Jolla, California-based Scripps Research Institute, whose laboratory created the new organism. Instead of two base pairs, it has a third.

All life on earth is based on the combination of four chemicals. Adenine bonds naturally with thymine to create the A-T section of the formula, while guanine and cytosine make up the C-G part. The joining of these base pairs in different combinations creates amino acids and proteins that power life.

Romesbergs work differs from other research in the field of genetic engineering in that it involves creation of components that are purely synthetic and integrated into the machinery of life in a cell, he said in a telephone interview.

Other scientists in the field, notably J. Craig Venter, work by constructing genetic material from natural building blocks, or natural components of DNA and proteins.

Starting in 2009, Romesberg and his laboratory created about 300 nucleotides with the newly constituted DNA before landing on ones they believed might be able to replicate in a cell. They then used a special chemical transporter to get the synthetic base pair into an E.coli cell, where it replicated without affecting cell growth. That suggests it wasnt recognized as atypical by the bodys natural DNA repair machinery, according to the paper.

Synthorx Inc., a San Diego-based biotechnology company, has exclusive rights to the synthetic biology from Scripps. The company plans to focus on developing the technology for use in vaccines, medicines and diagnostics, the company said today in a statement.

The research, though promising for fields of medicine and drug development, will probably raise ethical and safety concerns, said Arthur Caplan, head of the division of bioethics at NYU Langone Medical School. He called the research promising.

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Scientists Add New Letters to Lifes Genetic Alphabet

LOS ANGELES For possibly billions of years, the DNA blueprints for life on Earth have been written with just four genetic letters A, T, G and C. On Wednesday, scientists announced that they added two more.

In a paper published in the journal Nature, bioengineers at The Scripps Research Institute in the San Diego neighborhood of La Jolla said they had successfully inserted two synthetic molecules into the genome of an Escherichia coli bacterium, which survived and passed on the new genetic material.

In addition to the naturally occurring nucleotides adenine, thymine, guanine and cytosine, which form the rungs of DNAs double-helix structure, the bacterium carried two more base-pair partners, which study authors have dubbed d5SICS and dNaM.

For more than a decade, scientists have been experimenting with so-called unnatural base pairs, or UBPs, saying they may hold the key to new antibiotics, future cancer drugs, improved vaccines, nanomaterials and other innovations.

Until now, however, those experiments have all been conducted in test tubes.

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, lead study author Denis Malyshev, a molecular and chemical biologist at Scripps, said in a prepared statement.

The new genetic material did not appear to be toxic to the bacteria, and it only remains in the organisms genome under specific lab conditions. In a natural environment, the molecules nucleoside triphosphates degrade and disappear in a day or two. Once they disappear, the bacterium reverts back to its natural base pair arrangement.

Still, experts said insertion of the synthetic materials into E. colis genome was a milestone.

This definitely is a significant achievement, said Ross Thyer, a synthetic biologist at the University of Texas at Austin, who was not involved in the research. What Im most excited about is how this will help us answer some bigger evolutionary questions: Why has life settled on a specific set of bases?

Malyshev and colleagues went about creating the semi-synthetic bacterium by genetically engineering a stretch of ring-like DNA known as a plasmid.

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Scientists build life form that adds letters to genetic code

For possibly billions of years, the DNA blueprints for life on Earth have been written with just four genetic "letters" -- A, T, G and C. On Wednesday, scientists announced that that they added two more.

In a paper published in the journal Nature, bio-engineers at Scripps Research Institute in La Jolla said they had successfully inserted two synthetic molecules into the genome of an Escherichia coli bacterium, which survived and passed on the new genetic material.

In addition to the naturally occurring nucleotides adenine, thymine, guanine and cytosine, which form the rungs of DNA's double-helix structure, the bacterium carried two more base-pair partners, which study authors have dubbed d5SICS and dNaM.

For more than a decade, scientists have been experimenting with so-called unnatural base pairs, or UBPs, saying they may hold the key to new antibiotics, future cancer drugs, improved vaccines, nanomaterials and other innovations.

Until now, however, those experiments have all been conducted in test tubes.

"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," lead study author Denis Malyshev, a molecular and chemical biologist at Scripps, said in a prepared statement.

The new genetic material did not appear to be toxic to the bacteria, and it only remains in the organism's genome under specific lab conditions. In a natural environment, the molecules -- nucleoside triphosphates -- degrade and disappear in a day or two. Once they disappear, the bacterium reverts back to its natural base pair arrangement.

Still, experts said insertion of the synthetic materials into E. coli's genome was a milestone.

"This definitely is a significant achievement," said Ross Thyer, a synthetic biologist at the University of Texas at Austin, who was not involved in the research. "What I'm most excited about is how this will help us answer some bigger evolutionary questions: Why has life settled on a specific set of bases."

Malyshev and colleagues went about creating the semi-synthetic bacterium by genetically engineering a stretch of ring-like DNA known as a plasmid.

Read more from the original source:
Scientists add new letters to bacteria's genetic 'alphabet'