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Altering mosquito DNA is fine, but scientists shouldn't let mutants spread

Altering mosquito DNA is fine, but scientists shouldn't let mutants spread

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Expert panel urges caution for gene drive research

James Bareham

Scientists can genetically modify organisms to see if these changes might stop the spread of diseases like malaria, Zika, chikungunya, and dengue — but those genetically altered creatures better not spread throughout the world, a panel of scientists concluded today.

The panel, which was convened by the National Academies of Sciences, Engineering, and Medicine, looked at controversial research that aims to permanently alter the DNA of organisms with the intention of spreading those alterations quickly throughout a population — or even an entire species. The work, called gene drive research, could hypothetically be used to stop mosquitoes from spreading disease. But as the panel's report shows, saying saying "yes" to research isn't the same as approving it for general use. For now, whatever scientists do should be confined to the lab or highly controlled field environments, The New York Times reports.

not enough evidence that releasing altered insects will eliminate disease

Already, scientists have used gene-editing technology to make mosquitoes that can resist the parasite responsible for malaria. But, as today's report notes, there isn’t enough evidence that releasing these altered insects into the wild will actually eliminate disease. In addition, most scientific research also requires the consent of people who might be affected. In the case of a gene drive, obtaining that consent might be very difficult — if not impossible. Finally, these releases won't be governed by political boundaries, so what one country decides to do could have a global effect. So, even though the world faces threats from mosquito-related diseases, governments shouldn’t give in to the pressure to release a bunch of mutants just because people are asking for it.

Gene drives are a special, powerful kind of genetic alteration. They're specifically designed to spread a trait through the population — by way of its offspring. So, for instance, scientists might introduce a gene in mosquitoes that reduces the number of females in a population, thus limiting the insect's ability to grow and reproduce. But a gene alteration like that could also inadvertently jump to another population or even another species — and wreak havoc on an entire ecosystem. "The presumed efficiency of gene-drive modified organisms may lead to calls for their release in perceived crisis situations before there is adequate knowledge of ecological effects, and before mitigation plans for unintended harmful consequences are in place," the report states.

That's why some researchers continue to think that even small, controlled field experiments are too risky. "There is a nontrivial chance that they will spread from a single organism released into a wild population into most or all members of the local population — and very possibly into every population of the target species around the globe," Kevin Esvelt, a gene drive expert at MIT, told STAT. "This makes field trials of [current gene] drives unwise."