A research team from Imperial College London have published promising results of an experiment in which Anopheles gambiae mosquitoes — responsible for the spread of malaria — were genetically modified with a stable, gene-drive-based CRISPR modification that caused them to go extinct in the lab.
Importantly, the experiment showed that the modified snip of the mosquitoes' genome was kept stable by the gene drive, neither reverting to a neutralized version that would allow the mosquitoes' population to rebound, nor mutating in a way that might threaten other players in the mosquitoes' ecosystem.
The result raises important ethical questions about whether it would be safe and ethical to deliberately render a species extinct, even one as harmful to humans as Anopheles gambiae.
Crisanti dismisses the notion gene drives could be used to easily create new biological weapons. While he acknowledges the concerns, which have been considered by numerous scientific organizations, Crisanti and others argue the potential benefits far outweigh the risks.
"I regard a mosquito that transmits malaria as a pathogen — and as a pathogen we have the right to eliminate it," Crisanti says. "We have eliminated viruses like smallpox. We are trying to eliminate polio. I don't see a big difference."
The technology could also be used to target other disease-spreading insects, such as the species of mosquitoes that spread diseases including Zika and dengue. Gene drives could also be used to fight agricultural pests.
Mosquitoes Genetically Modified To Crash Species That Spreads Malaria [Rob Stein/NPR]
A CRISPR–Cas9 gene drive targeting doublesex causes complete population suppression in caged Anopheles gambiae mosquitoes [Kyros Kyrou, Andrew M Hammond, Roberto Galizi, Nace Kranjc, Austin Burt, Andrea K Beaghton, Tony Nolan & Andrea Crisanti/Nature Biotechnology]
