Posted on 11/18/2012 8:50:35 PM PST by LibWhacker
Scientists and engineers dream about big advances that could change the world, and then they try to create them. On the following pages, Scientific American reveals 10 innovations that could be game changers: an artificial alternative to DNA, oil that cleans water, pacemakers powered by our blood, and more. These are not pie-in-the-sky notions but practical breakthroughs that have been proved or prototyped and are poised to scale up greatly. Each has the potential to make what may now seem impossible possible. —The Editors
New Life-Forms, No DNA Required Artificial organisms based on man-made molecules could thrive and evolve
DNA is passé. Synthetic biologists have invented an array of new molecules called XNAs that boast all the talents of deoxyribonucleic acid (DNA) and ribonucleic acid (RNA), as well as some special powers. XNAs could allow scientists to safely create life-forms in the laboratory that do not depend on DNA to survive and evolve.
“Life is inconceivable without a system for genetic information storage and replication, but DNA and RNA are not unique,” explains Philipp Holliger of the Medical Research Council's Laboratory of Molecular Biology in Cambridge, England. “Related polymers—at least six more—can do the same function.” That the earth's flora and fauna rely only on DNA and RNA, he says, is an “accident from the origin of life.”
XNA stands for xeno nucleic acid (xeno meaning “foreign”). Like DNA, XNA has a structure that resembles a twisted ladder. In DNA, four different nucleobases, represented by the letters A, C, G and T, form the steps. Phosphate groups and sugars form the ladders' sides, also known as the backbone. For 30 years scientists have been tweaking the sugars to create artificial nucleic acids, which serve as research tools in medicine that can bind to DNA.
To make XNAs, Holliger and his colleagues did not simply alter the sugars in DNA's backbone—they substituted entirely different molecules, such as cyclohexane and threose. Just as important, they created enzymes that work with the XNAs to form a complete genetic system.
The enzymes enable XNAs to do something no other artificial nucleic acids can do: they evolve. Inside living cells, enzymes called polymerases cut, paste and splice DNA to access the genetic information. Without that interaction, DNA would remain as inert as dusty encyclopedias on a shelf. Holliger reprogrammed natural polymerase enzymes to translate DNA into XNA and back again, establishing a novel system for storing and transmitting genetic information, which is the foundation of evolution. One of the XNAs, HNA (anhydrohexitol nucleic acid), reliably preserved changes to its genetic code and evolved to attach to a protein with increasing precision.
Once Holliger improves the functionality of XNA and its enzymes, the set of molecules could replace DNA and RNA in a living cell. Researchers might take a simple bacterium, for instance, suck out its DNA and replace it with XNA.
Alternatively, scientists could enclose XNA within protocells—the origin of a new life-form that could evolve in ways no one can predict. Whereas other synthetic biologists such as J. Craig Venter have made remarkable advances in rewriting the existing genetic code, no one has created truly synthetic life—life that does not depend on what evolution has already provided but on humankind's inventions.
Holliger emphasizes that XNA-based life-forms are a long way off, but he already recognizes a distinct advantage. If such a creature escaped into the wild, it would die without a steady supply of XNA-specific enzymes. And XNA could not weave itself into the genomes of natural organisms, because their native enzymes would not recognize it. XNA-based bacteria designed to devour oil spills or turn wastewater into electricity, for example, could not interfere with native organisms.
The fact that XNA is complementary to DNA, yet structurally unique, makes it immediately useful for medicine, biotechnology and biology research. Holliger imagines XNAs that could be injected into the human body to detect early, subtle signs of disease that current technologies miss.
Steven Benner, a fellow at the Foundation for Applied Molecular Evolution in Gainesville, Fla., has also advanced the effort by expanding the genetic alphabet with two new nucleobases, Z and P. A larger alphabet could form a wider array of genes and, eventually, proteins. “The goal is to create chemically controlled systems that behave like biological systems, without being biological systems,” Benner says. “We believe whatever you can draw on a page, you can make.” — Ferris Jabr
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(Excerpt) Read more at http://www.scientificamerican.com/article.cfm?id=world-changing-ideas-2012-innovations-radical-enough-alter-lives&print=true
Sorry about not posting the whole thing. Seemed overly long.
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Some of these are cool, the other is like the Borg collective meets 1984.
Scariest part of all is what a gentleman who worked with my father said years ago. He was former military intelligence, and he said that if you are hearing about it now, it’s likely the military has had it for a decade.
The future does not look bright.
Define “safely”.
New life forms.
They don’t recognize the old life forms.
A fetus is not a life form to them, synthetic DNA is.
Photosynthesis is old hat I guess.
No, of course not, unless some natural creature had a naturally occurring mutation producing an enzyme close enough, which we know never happens, right?
I have a good idea .... my idea is fly paper that attracts stink bugs. I bet the military hasn’t thought of this one yet.
11. Pensions and perks of all legislators past and present rescinded for not reducing/eliminating the debt.
That would DEFINITELY alter our lives. For the better. Thank you.
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