Finding by HSPH Researchers Could Aid in Malaria Control

In a finding that could advance malaria control, researchers from the Harvard School of Public Health and the University of Perugia, in Italy, have identified a way to block a reproductive interaction in malaria-transmitting mosquitoes.

The researchers’ study, published online on Oct. 29 in the open-access journal PLOS Biology, identifies the gene in the mosquito species Anopheles gambiae—the species most responsible for the spread of malaria—that regulates the number of offspring produced by the female.

The researchers found that when these mosquitoes mate, that gene in the female is activated by a steroid hormone from the male. By blocking this switch, the researchers concluded, they can control egg development and reproduction in the species, thereby reducing the number of mosquitoes transmitting the disease.

Adam South, a School of Public Health postdoctoral fellow and co-author of the study, said his team’s results were surprising because it is “kind of unusual for a female’s offspring to be so intimately tied to something coming from a male.”

South said that controlling transmission of the disease is “the most effective means of controlling malaria.”

School of Public Health professor Flaminia Catteruccia, another co-author of the study, named two ways in which the team’s results could help combat the spread of malaria.

One option, she said, could be to manipulate males so that they will not produce and transfer a functional hormone. A second possibility would be to design inhibitors of the gene to prevent females from developing eggs. These inhibitors could be incorporated into insecticide so that mosquitoes not killed by insecticide would, at the very least, not produce offspring.

“This would increase the lifespan and efficacy of insecticides, our best weapon against malaria and mosquitoes,” Catteruccia said.

Catteruccia and South both said they hope Harvard students recognize the importance of the scientific research going on around them. “I think it will be inspiring for students to realize that basic biology research carried out at Harvard can in the long run make a difference for global health,” Catteruccia said.

Malaria results when infected mosquitoes bite humans, transmitting a parasite that infects human red blood cells. According to the World Health Organization, there were an estimated 219 million malaria cases and 660,000 resultant deaths worldwide in 2010. Ninety percent of all deaths occurred in the African region that year.