The researchers, whose work was published on Monday in the journal
Nature Biotechnology, managed to eliminate the population in less
than 11 generations, suggesting the technique could in future be
used to control the spread of malaria, a parasitic disease carried
by Anopheles gambiae mosquitoes.
"It will still be at least five to 10 years before we consider
testing any mosquitoes with gene drive in the wild, but now we have
some encouraging proof that we're on the right path," said Andrea
Crisanti, a professor at Imperial College London who co-led the
The results mark the first time this technology has been able to
completely suppress a population. The hope is that in future,
mosquitoes carrying a gene drive could be released, spreading female
infertility within local malaria-carrying mosquito populations and
causing them to collapse.
Gene drive technologies alter DNA and drive self-sustaining genetic
changes through multiple generations by overriding normal biological
processes. The technologies can be very powerful, but they are also
controversial, since such genetically engineered organisms released
into the environment could have an unknown and irreversible impact
on the ecosystem.
The technique used in this study was designed to target the specific
mosquito species Anopheles gambiae that is responsible for malaria
transmission in sub-Saharan Africa.
The World Health Organization has warned that global progress
against malaria is stalling and could be reversed if momentum in the
fight to wipe it out was lost.
The disease infected around 216 million people worldwide in 2016 and
killed 445,000 of them. The vast majority of malaria deaths are in
babies and young children in sub-Saharan Africa.
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Crisanti's team designed their gene drive to selectively alter a
region of a so-called "doublesex gene" in the mosquitoes, which is
responsible for female development.
Males who carried this modified gene showed no changes, and neither
did females with only one copy of it, he explained in the study. But
females with two copies of the modified gene showed both male and
female characteristics - they failed to bite and did not lay eggs.
The experiments found the gene drive transmitted the genetic
modification nearly 100 percent of the time, and after 7-11
generations the populations collapsed due to lack of offspring.
Crisanti said the results showed that gene drive solutions can work,
offering "hope in the fight against a disease that has plagued
mankind for centuries".
He added, however, that "there is still more work to be done, both
in terms of testing the technology in larger lab-based studies and
working with affected countries to assess the feasibility of such an
But Mariann Bassey, a campaigner with the environmental group
Friends of the Earth Africa, said the technique was risky.
"To solve the malaria crisis, we should focus on the least risky and
most effective solutions, not experiment with ecosystems with little
regard for the potentially new environmental and health
consequences," she said in a statement.
(Reporting by Kate Kelland; Editing by Matthew Mpoke Bigg)
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