Researchers in the United Kingdom have stopped mosquitoes from reproducing via genetic modification, raising the hope that they could eventually eliminate them in the wild. Scientists at Imperial College, London completely blocked the reproductive ability of the Anopheles gambiae mosquito, which spreads malaria, eliminating the lab population within seven to 11 generations through the use of a technique called gene drive.
Malaria is caused by parasites that are transmitted to people through the bites of infected female Anopheles mosquitoes.
The incidence rate of malaria is estimated to have decreased by 18 per cent globally, from 76 to 63 cases per 1000 population at risk, between 2010 and 2016. However, Sub- Saharan Africa, accounts for 99 per cent of estimated malaria cases in 2016. On its part, Nigeria suffers the world’s greatest malaria burden, with approximately 51 million cases and 207,000 deaths reported annually (approximately 30 per cent of the total malaria burden in Africa), while 97 per cent of the total population (approximately 173 million) is at risk of infection. Despite significant reductions in cases in the last two decades, malaria remains the biggest killer of children under five in Africa.
In 2016, there were 216 million cases of the disease worldwide, resulting in an estimated 445,000 deaths overall. Lead researcher from the Department of Life Sciences at Imperial Professor Andrea Crisanti said the breakthrough that stopped mosquitoes from reproducing via genetic modifications, shows that gene drive could work, adding that it provided hope in the fight against a disease that has plagued mankind for centuries.
“There is still more work to be done, both in terms of testing the technology in larger lab-based studies and working with affected coun- tries to assess the feasibility of such an intervention.” This latest study is a major step towards eradicating malaria-carrying mosquitoes in the wild, by spreading female infertility. The scientists targeted the double-sex gene, which determines the mosquito’s sex, through a technique called gene drive. The technique spreads a gene, or particular suite of genes, through a population via reproduction.
Males who carried the genetic modification saw no changes, and neither did females with only one copy of the gene. But females with two copies showed both male and female characteristics, failed to bite and did not lay any eggs, ‘The Telegraph’ reported. Professor Crisanti said: “It will still be at least five to 10 years before we consider testing any mosquitoes with gene drive in the wild, but now we have some encouraging proof that we’re on the right path.”