Radical DNA Future--Genetic Engineering Squared

Now that scientists are learning to insert artifical nucleic acid bases into DNA sequences, we are off for a wild ride in genetic engineering. Combining artificial nucleic acids with artificial amino acids should yield radically new peptides and enzymes, with designable shapes and characteristics.

Two artificial DNA "letters" that are accurately and efficiently replicated by a natural enzyme have been created by US researchers. Adding the two artificial building blocks to the four that naturally comprise DNA could allow wildly different kinds of genetic engineering, they say.

Eventually, the researchers say, they may be able to add them into the genetic code of living organisms....The unnatural but functional new base pair is the fruit of nearly a decade of research by chemical biologist Floyd Romesberg, at the Scripps Research Institute, La Jolla, California, US.

Romesberg and colleagues painstakingly created a library of nearly 200 potential new genetic bases that are slight variations on the natural ones. Unfortunately, none of them were similar enough in structure and chemistry to the real thing to be copied accurately by the polymerase enzymes that replicate DNA inside cells....The team is now eager to find out just what makes it work. "We still don't have a detailed understanding of how replication happens," says Romesberg. "Now that we have an unnatural base pair, we are continuing experiments to understand it better."

In the near future, Romesberg expects the new base pairs will be used to synthesize DNA with novel and unnatural properties. These might include highly specific primers for DNA amplification; tags for materials, such as explosives, that could be detected without risk of contamination from natural DNA; and building novel DNA-based nanomaterials....Romesberg notes that DNA and RNA are now being used for hundreds of purposes: for example, to build complex shapes, build complex nanostructures, silence disease genes, or even perform calculations. A new, unnatural, base pair could multiply and diversify these applications.

The most challenging goal, says Romesberg, will be to incorporate unnatural base pairs into the genetic code of organisms. "We want to import these into a cell, study RNA trafficking, and in the longest term, expand the genetic code and 'evolvability' of an organism."

New Scientist
Initially, the new DNA's will be used to study replication, then altered transcription and translation. But soon, all bets are off. Other artificial base pairs will be designed and built, and we will be off to the races.

Such discoveries illustrate how limited our understanding of basic life processes have been. If the enemies of genetic engineering thought they understood "the enemy," they could not have been more wrong.

More information at links at Brian Wang's NextBigFuture