Scientists working at the cutting-edge of genetics say one possible application of a powerful new technology called genome editing has the potential to cause ecological mayhem and needs attention from regulators.
The technique, referred to as a “gene drive,” would cause chosen genes, including man-made ones, to quickly spread through a species as its members reproduce. While gene drives may have commercial and public health uses, 10 scientists published an editorial today in the journal Science calling for more public discussion, and also more scrutiny by regulators.
A news report in Science gives the background:
[A] gene drive involves stimulating biased inheritance of particular genes to alter entire populations of organisms. It was first proposed more than a decade ago, and researchers have been developing gene drive approaches to alter mosquitoes to slow the spread of malaria and dengue fever. Although progress has been quite slow, recent advances in gene editing could lead to a rapid application of gene drive approaches to other species.
Usually, the chance of a gene being passed on to offspring is 50 percent, but it’s possible to engineer an organism’s chromosomes to alter those odds. Researchers have already used the idea to design mosquitoes that only make male offspring, with the idea of releasing them in the wild to cause a population crash, thereby reducing malaria. The technology has also been contemplated as a way to spread genes that would make weeds more susceptible to herbicides like RoundUp. Ironically, some weeds have become resistant to the chemical because it is sprayed heavily on crops that had themselves been genetically engineered to resist the spray.
According to the authors of the editorial, who include Kenneth Oye, a political scientist at MIT, as well as James Collins, an expert in genetic engineering at Arizona State University, “gene drives present environmental and security challenges.”
Even though the idea of driving particular traits to spread through a species isn’t new, what worries the scientists is that new genome editing methods, known as CRISPR/Cas9, will make it much easier to do (see “Genome Surgery”). In a separate article, published in another journal today, scientists from Harvard University, led by George Church, say they’ve created big advances to the method which people need to start worrying about:
Gene drives may be capable of addressing ecological problems by altering entire populations of wild organisms, but their use has remained largely theoretical due to technical constraints.
With recent improvements in the technology, however:
The possibility of unwanted ecological effects and near-certainty of spread across political borders demand careful assessment of each potential application.
The fear is that the gene drives might run amok and affect wild populations of plants, animals, or insects. The faster an organism reproduces, the quicker a gene could spread. Any gene variants given an artificial boost could eliminate other versions of those genes, whose potential evolutionary importance scientists have no idea of. Also, the technology could be used to create weapons that destroy agricultural crops or create super pests.
Back in the 1970s, when scientists first learned to alter DNA, they imposed a voluntary moratorium on their work, until its safety could be better understood. Today, genetic research is moving even faster, but with few if any constraints on laboratory science.
But before this kind of research moves into practice, the scientists who authored the editorial say society needs to develop “integrated risk management” including genetic antidotes that could reverse the effect, and “long-term studies [to] evaluate the effects of gene drive use on genetic diversity in target populations.”
In short, the scientists guarding the hen house say they need help. Their editorial concludes:
For emerging technologies that affect the global commons, concepts and applications should be published in advance of construction, testing, and release. This lead time enables public discussion of environmental and security concerns, research into areas of uncertainty, and development and testing of safety features. It allows adaptation of regulations and conventions in light of emerging information on benefits, risks, and policy gaps. Most important, in the case of gene drives, lead time will allow for broadly inclusive and well informed public discussion to determine when and how gene driver should be used.
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