Malaria has long been a persisting problem particularly in developing countries where many die of the disease. Although countries have adopted measures to curb the prevalence of the malaria, its death toll remains high with over 627,000 dying of the disease in 2012. Releasing a new breed of genetically modified mosquitoes to the wild, however, may possibly put an end to this global health problem.
Malaria, a potentially fatal disease characterized by high fever and vomiting, is transmitted to humans through the bite of infected mosquitoes. Because male mosquitoes only feed on flower nectar, malaria and other mosquito-borne diseases are transmitted by female mosquitoes, which need to feed on the blood of humans and animals to reproduce.
On the premise that distorting the sex ratio of mosquito populations by eliminating female mosquitoes can reduce the number of the disease-carrying pests and wipe out malaria, a group of researchers genetically modified mosquitoes so they would only produce male offspring.
For a new study published in the journal Nature Communications on June 10, researchers from the Imperial College London tested a new method that would cause mosquitoes to have sperm that only produces male offspring.
"We combine structure-based protein engineering and molecular genetics to restrict the activity of the potentially toxic endonuclease to spermatogenesis," the researchers said of their technique. "Shredding of the paternal X chromosome prevents it from being transmitted to the next generation, resulting in fully fertile mosquito strains that produce >95% male offspring."
The researchers then introduced this special breed of mosquitoes to caged normal Anopheles gambiae mosquitoes, the particular species of mosquito responsible for transmitting the malaria-causing Plasmodium parasite. Within six generations, the population of the mosquitoes in four out of the five cages in the study was eliminated because they cannot reproduce for lack of females.
The technique the researchers used in the study may prove a feasible means of wiping out malaria if successfully replicated in the wild. Study researcher Nikolai Windbichler, from the Department of Life Sciences at Imperial College London, said that the most promising thing about their study is that process they employed to eliminate mosquitoes is self-sustaining.
"Once modified mosquitoes are introduced, males will start to produce mainly sons, and their sons will do the same, so essentially the mosquitoes carry out the work for us," Windbichler said.
Study researcher Roberto Galizi, also from the Department of Life Sciences at Imperial College London, said that their goal is to help people live their lives without the threats of malaria. He said that the approach they used in their study could be a cheap and effective means of eliminating the deadly disease.