Scientists have hailed the genetic modification of mosquitoes that could crash the insect’s populations as a “quantum leap” that will make a substantial and important contribution to eradicating malaria.

 

Previous efforts to tackle the disease, that kills more than 1 million people each year – most of whom are African children – have included bed nets to protect people and insecticides to kill the mosquito species most responsible for the transmission of malaria (Anopheles gambiae).

 

The new technique by a team at Imperial College London involves injecting mosquitoes with a gene that causes the vast majority of their offspring to be male, leading to an eventual dramatic decline in population within six generations as females disappear.

 

The scientists injected mosquitoes with a gene from slime mould – a homing endonuclease called I-PpoI – which attached itself to their X chromosome during the male’s sperm-making process and effectively shredded part of the chromosome’s DNA. The result was that more than 95% of the mosquitoes offspring were males. The researchers found that the modified mosquitoes mated with wild mosquitoes, creating fertile mosquitoes which then overwhelmingly produced male offspring, passing on the gene.

 

Nikolai Windbichler, a research fellow at Imperial College London and co-author, said that the concept of distorting the sex of a pest’s population is more than 50 years old but that the technology had not been available until now to execute the idea.