Male-only mosquitoes to conquer malaria
Mosquitoes have been genetically modified to give birth only to males in a technique that scientists hope could help wipe out malaria.
The disease is spread by female mosquitoes, which feed on blood to get the protein needed for their eggs.
Researchers from Imperial College London inserted a DNA- cutting enzyme called I-PpoI into Anopheles gambiae mosquitoes, the main carrier of the malaria parasite.
In normal reproduction, half of the sperm bear the X chromosome and will produce female offspring. But in the first laboratory tests where modified mosquitoes had been mixed with normal insects, 95pc of the eggs hatched were males.
It is hoped that if replicated in the wild, the technique would cause the malaria-carrying mosquito to die out within a few generations.
Dr Nikolai Windbichler, a lead researcher at Imperial College, said: "What is most promising about our results is that they are 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."
The scientists introduced the genetically modified mosquitoes to five caged normally wild mosquito populations. In four of the five cages, this eliminated the entire population within six generations due to the lack of females.
Worldwide, there are more than 200 million malaria cases per year and more than 650,000 deaths, mostly in African children under five. (© Daily Telegraph, London)