Synthetic Genetic Evolution | The Scientist: To see whether XNAs could evolve, they generated random HNA sequences, then selected for those that could bind to two target molecules. After selection, the HNAs were amplified by the newly designed polymerases and again selected for their ability to bind the targets. Eight rounds of selection later, the HNA sequences were no longer random, as those with a particular target-binding motif became more abundant. Through selection and replication, the HNAs had evolved.
The finding in itself is not surprising, said Kool. “Chemists have been working for 20 years to find new backbones for DNA and the feeling always was that it would be interesting and quite possible that some of them might be replicated one day.” It was, nevertheless, impressive, he added. “The hard part was finding the enzymes that could do it. So the big leap ahead for this paper was finding those enzymes.”