To your molecular biology vocabulary, add the term XNA.
The X, as Eryn Brown wrote in the Los Angeles Times, is from the Greek xeno, the prefix meaning strange or alien. Thus, “strange nucleic acid” or, for more fun, “alien nucleic acid,” the kind of genetic molecule than an extraterrestrial might have.
Researchers in Cambridge, England, have built six different kinds of nucleic acid that don’t exist in nature, at least not on Earth. For the deoxyribose part of the molecule, the D, they substitute such other molecules as cyclohexene and anhydrohexitol. Give those molecules the usual bases–A, T, G and C–and they work just fine, at least in laboratory experiments. For example, the code could be read by engineered enzymes, polymerases, that transcribed the message into normal DNA. The researchers also showed that XNAs could evolve, since rare copying errors showed up and worked well in further copying.
Brown’s story is decent but includes the widely used but often lame so-what claim that the findings “could” help scientists develop new drugs.
The Philadalphia Inquirer‘s Faye Flam phrases a similar answer to the question this way: “The work on XNA molecules adds to a growing field of test-tube evolution, in which scientists are nudging code-carrying chemicals to evolve into drugs or other useful compounds.”
Robert Langreth of Bloomberg Businessweek answered the so-what question with familiar hyperbole: “Scientists moved a step closer to synthesizing new life forms in the laboratory …” But he then goes on to discuss the business implications with some drug-development comments that seem more convincing than the naked claim in Brown’s story.
Other takes: Christine Dell’Amore in National Geographic News; Ian Sample at the Guardian (UK).
-Boyce Rensberger
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