Scientists prove new technology to control malaria-carrying mosquitoes

Scientists at Imperial College London and the University of Washington, Seattle, have taken an important step towards developing control measures for mosquitoes that transmit malaria.
In a new  study, published in Nature, researchers have demonstrated how some genetic changes can be introduced into large laboratory mosquito populations over the span of a few generations by just a small number of modified mosquitoes.

In the future this technological breakthrough could help to introduce a genetic change into a mosquito population and prevent it from transmitting the deadly malaria parasite, Plasmodium, to humans.

Malaria is a debilitating disease that affects more than 300 million people every year, and kills nearly 800,000 annually. In Africa, a child dies of malaria about every 45 seconds. Public health experts have called for malaria eradication, but there is a recognised need for better and lower cost tools to achieve the eradication goal. Scientists around the world are keenly seeking novel strategies to tackle malaria.

The researchers bred mosquitoes with a green fluorescent gene, as a marker that can easily be observed in experiments. They allowed these insects to mingle and mate with a small number of mosquitoes that carried a segment of DNA coding for an enzyme capable of permanently inactivating the fluorescent gene. After each generation, they counted how many mosquitoes still retained an active fluorescent gene.

They found that in experiments which began with close to 99% of green fluorescent mosquitoes, more than half had lost their green marker genes in just 12 generations. The study is the first successful proof-of-principle experiment of its kind, and suggests that this technique could similarly be used to propagate a genetic change within a wild mosquito population.

Professor Andrea Crisanti, from the Department of Life Sciences at Imperial College London, a senior author of the study and head of the research group, said: "This is an exciting technological development, one which I hope will pave the way for solutions to many global health problems.

It demonstrates significant potential to control these disease-carrying mosquitoes. We expect to conduct many more experiments to determine its safety and reliability."