Malaria-proof mosquito? Tool promising but needs more study
WASHINGTON — A powerful new technology holds the promise of rapidly altering genes to make malaria-proof mosquitoes, eliminate their Zika-carrying cousins or wipe out an invasive species, but a report Wednesday says these “gene drives” aren’t ready to let loose in the wild just yet.
Advisers to the government say lots more research is needed to learn to safely use gene drives and understand the ecological and social consequences of essentially hijacking evolution, spreading genetic changes through populations of insects, animals or certain plants faster than nature.
And the public, around the world, needs a say in whether and how gene drives eventually are used, especially because some may be intended for lowincome countries, stressed the National Academies of Sciences, Engineer and Medicine.
“Public engagement cannot be an afterthought,” said Vanderbilt University medical ethicist Elizabeth Heitman, who co-chaired the National Academies’ committee.
Gene drives are on the horizon. Already, a California lab has hatched mosquitoes that spread a malaria-blocking gene every time they reproduce. Researchers say it should be possible to eliminate populations of another mosquito — the kind that spreads the Zika virus and dengue fever — by making them sterile.
Another possible use
Similarly, gene drives one day might be used to wipe out invasive species such as rodents that devastate native plants and animals on many of the world’s islands, without toxic chemicals. Or they might help reverse pesticide resistance in a crop-suffocating weed.
“The gene drive approach could offer a safer, less expensive and more lasting solution” to many problems, said National Academies’ committee member Jason Delborne, an associate professor of science, policy and society at North Carolina State University.
But the report called for cautious, phased-in research given questions about the technology’s impact. It said gene drives should be studied first in laboratories before moving to tightly controlled field trials — in greenhouses, screened cages or even on remote islands, to lower any risk of escape — to help determine if organisms modified in this unique way ever should be released into the environment.
Findings hailed
The National Institutes of Health, which requested the report, welcomed the findings.
“This approach to potential irreversible modification of the genome of an entire species is breathtaking,” said NIH Director Dr. Francis Collins.
No one knows how rapidly altering entire populations could affect habitats. What if wiping out invasive species lets something worse fill that empty niche? What happens if an alteration spreads to an unintended species?
Moreover, gene drives would spread with no regard for national borders, the panel warned. It called for international scientific and regulatory collaboration, and noted that even in the United States, it’s not clear who’s in charge.
Consider those island rodents: Would a gene drive in a mouse be governed as an animal drug by the Food and Drug Administration, or a rodent poison by the Environmental Protection Agency, or a plant pest by the Agriculture Department?