Artificial DNA Presents Real Dangers
As concerns grow about dangers posed by the emergent field of synthetic biology, a novel discovery threatens to make this “extreme” form of genetic engineering even more risky.
Since Watson and Crick discovered the double-helix structure
of DNA in 1953, it’s been a common assumption that DNA and RNA are the
only molecules that can store genetic information and pass it on. That
belief, according to a recent article in Science, may no longer hold.
New Discoveries in Synthetic Biology - XNA
The article’s conclusion is summarized by its title, “Synthetic
Genetic Polymers Capable of Heredity and Evolution.” "There is nothing
Goldilocks about DNA and RNA," noted Phillip
Holliger, a co-leader along with Vitor Pinheiro of the research team
who authored the paper. "There is no overwhelming functional imperative
for genetic systems or biology to be based on these two nucleic acids."
DNA, as one article about the new study puts it, no longer has “reason to feel special.”
Holliger and Pinheiro's team of researchers, based at the MRC Laboratory of Molecular Biology
in Cambridge, UK, demonstrated that six alternative nucleic acids are
capable of storing and transmitting genetic information. These
molecules, collectively dubbed XNAs or Xeno-Nucleic-Acids (“Xeno” is
Greek for foreign or alien) carry the same nucleic acid base pairs as do
DNA and RNA (the well-known A, C, T, and G), but do so on a sugar backbone different from the deoxyribose of DNA or the ribose of RNA.
The Cambridge team induced one of the XNAs to undergo an evolution-like process, thus demonstrating that “replication, heredity and evolution are possible in these alternative [XNA] backbones.”
Just as significant is the set of techniques developed in
conducting the research. XNAs have been in scientific use for some
time, but scientists used to have to make them one at a time, limiting
their experimental value. The new research has made that process
obsolete. As one researcher put it, “if I give you a few XNAs in the
morning, I can come back in the afternoon and you can give me trillions
of copies.”
Media Buzz and Scientific Hype
The study has been greeted with a wave of media buzz not seen for synthetic biology since Craig Venter’s team declared they had created the first (so-called) synthetic life form back in 2010. Prominent articles covered it excitedly in the, Los Angeles Times, Boston Herald, The Guardian, Scientific American, New Scientist, and BBC News, just to name a few.
The scientific community has also been enthusiastic. One of the study’s authors, molecular biologist John Sutherland, called the discovery a “game changer.” In a commentary in Science titled
“Toward an Alternative Biology,” Gerald Joyce, a researcher at the
Scripps Research Institute who is unaffiliated with Holliger’s team, proclaimed that:
The work heralds the era of synthetic genetics, with implications for exobiology, biotechnology, and understanding of life itself.
The work done by Holliger and his team is no doubt scientifically significant. However, it is just as significant for the new risks it poses. It is worth summarizing some of the projected applications and risks of this new research.