Malaria-resistant mosquitoes outbreed others: study

WASHINGTON (Reuters) - Mosquitoes genetically engineered to resist infection with a malaria parasite outbreed their normal cousins and might be used to help control malaria, U.S. researchers said on Monday.

They found that releasing these genetically altered insects could help battle malaria, which kills up to 3 million people a year around the globe, most of them small children.

Marcelo Jacobs-Lorena and colleagues at Johns Hopkins University in Baltimore studied mosquitoes with an extra gene spliced in that helps stop them from transmitting the parasite, the research model of the parasite.

Previous studies have already shown that these mosquitoes are perfectly healthy.

Jacobs-Lorena and colleagues studied the mosquitoes as they bred in cages. The mosquitoes were allowed to feed on mice that had been infected with Plasmodium berghei, the parasite used as the research model. P. falciparum is the parasite the mosquitos carry that causes malaria.

The transgenic mosquitoes were more fertile and less likely to die than normal, wild mosquitoes, they report in this week's issue of the Proceedings of the National Academy of Sciences.

They also began to outbreed the normal mosquitoes.

"To our knowledge, no one has previously reported a demonstration that transgenic mosquitoes can exhibit a fitness advantage over nontransgenics," the researchers wrote.

They ran a computer program projecting how much better the gene-engineered mosquitoes would do and it predicted engineered insects would have a 50 percent better survival rate.

The researchers said their study shows the idea of using lab-engineered mosquitoes to battle malaria is a valid one.