Scientists alter mosquito genes to end malaria

15 December 2015

The mosquito menace may soon be over, thanks to new genes introduced to the Anopheles gambiae mosquitoes, the variety that spreads the disease across sub-Saharan Africa, by inducing infertility in female offspring.

According to a team at Imperial College London, led by molecular biologist Tony Nolan and vector biologist Andrea Crisanti, the gene would lead to infertility, and spread quickly among the population.

As a result, females carrying two copies of the gene would not be able to breed.

According to the journal Nature, 75 per cent of mosquitoes harboured the mutations after four generations. Professor Nolan told the BBC, the work could be done without a major impact on ecosystems.

He said, "There are roughly 3,400 different species of mosquitoes worldwide and, while Anopheles gambiae is an important carrier of malaria, it is only one of around 800 species of mosquito in Africa, so suppressing it in certain areas should not significantly impact the local ecosystem."

If the females had just one copy of the gene, natural selection meant they would pass on the healthy version as opposed to the infected gene.

Normally, each gene variant had 50 per cent chance of being passed down from parents to their offspring, however, the team's experiment showed the gene for infertility was transmitted to more than 90 per cent of the offspring of both male and female mosquitoes.

The scientists identified three genes in Anopheles gambiae that lead to infertility in females.

However, not everyone was convinced the modification would work as intended.

Kevin Esvelt, an evolutionary engineer at Harvard University in Cambridge, added, "I really like this paper. It's a beautiful piece of work," express online reported.

"It's hard to imagine that the parasite will not evolve resistance to whatever we do to mosquitoes."

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