In the quest to squelch malaria, biotechnologists have sketched plans to introduce a gene into mosquitoes that would confer resistance to the malaria parasite, Plasmodium falciparum, which the insects transmit between people. Now it seems that nature may have beat researchers to the punch. A group collected thousands of Anopheles gambiae mosquitoes from huts in Mali and let some of their offspring feed on blood from an infected villager. Of 101 different pedigrees, a surprising 22 showed no trace of Plasmodium on dissection, reports the group in the April 28 Science. The resistance appears to stem from a gene or genes on a small patch of chromosome the researchers have dubbed the Plasmodium resistance island. Lead author Kenneth Vernick of the University of Minnesota speculates that another strategy to combat malaria might be to selectively target bugs carrying the susceptibility gene variant, perhaps with a recently discovered lethal fungus that appears to prefer Plasmodium-ridden mosquitoes.
This article was originally published with the title "Island of Resistance" in Scientific American 295, 1, 33 (July 2006)