How an Altered Strand of DNA Can Cause Malaria-Spreading Mosquitoes to Self-DestructEnlarge this image toggle caption Dunpharlain/Wikimedia Commons Dunpharlain/Wikimedia CommonsScientists have demonstrated for the first time that genetic engineering can reduce populations of malaria-spreading moths.Researchers placed genetically modified mosquitoes into a laboratory to simulate the conditions found in sub-Saharan Africa. They then spread the deadly disease.The male mosquitoes have a genetic sequence known as "gene drive", which can quickly transmit a harmful mutation that effectively wipes out the insect population.Our goal is to develop a new powerful tool to combat malaria, one of the most devastating scourges in the world."Our study is the only one that could prove that gene-drive technology can work under ecologically difficult conditions," Ruth Muller, an Italian entomologist, said. She was the leader of the research at PoloGGB in Terni. "This is the major breakthrough we achieved with our study."This research was supported by the Bill and Melinda Gates Foundation. They are also sponsors of NPR and this blog.Additional research over many years will be required to confirm that the method works. The mosquitoes can then be released into the wild. Local residents would need to consent to the project and give their approval. This is mostly for areas in sub-Saharan Africa, Asia and other parts of Africa.Despite many years of effort, malaria is still a serious health problem. More than 200 million people are affected by the mosquito-borne parasitic illness every year. It also kills over 400,000 people each year, many of them children.Muller and her coworkers decided to use CRISPR. This technique allows scientists to make precise DNA changes to genetically alter the Anopheles.gambiae mosquito species that spreads malaria in sub Saharan Africa.This modification was caused by a mutation in the gene "doublesex," which is essential for female mosquitoes' normal development. Their mouths are affected, and they can't bite or spread the parasite. It also causes them to lose their reproductive organs and is unable for them to lay eggs.Tony Nolan, from the Liverpool School of Tropical Medicine who developed and tested the mosquitoes, says that the mutation can be combined with a genetic drive.The researchers took extraordinary measures to stop the insects from fleeing, fearing that they could disrupt the delicate ecosystem balance. Scientists first tested the mosquitoes at a London basement lab. There, the mosquitoes were able to destroy unmodified mosquitoes kept in small cages.Researchers in Italy built a high-security laboratory to test the mosquitoes' gene-drives. To prevent mosquitoes from escaping, everyone who entered the most secure area of the lab needed to go through a special chamber. In case any mosquitoes did manage to escape, the lab was deliberately located far away from Africa.Researchers then released hundreds of the gene-drive moths into large, specially designed cages that contained hundreds of natural mosquitoes. The cages in Italy were larger than those in London and replicated the sub-Saharan African environment, including temperature and humidity, and the time of sunrise and sunset.According to the study authors, gene-drive mosquitoes destroyed natural mosquito populations in less that a year.Others are also welcoming this advance.Anthony James, a professor of genetics and microbiology at the University of California Irvine, says that "it is a step forward in the right direction." He is currently conducting similar research. It's very important.Jeantine Lunshof is a bioethicist at Harvard University's Wyss Institute for Biologically Inspired Engineering.She says, "I believe the benefits are so great that I haven't found convincing arguments that it would have significant detrimental effects."Others are skeptical, and believe the technology is too risky.Nnimmo bassey, head of the Health of Mother Earth Foundation, a Nigerian environmental advocacy group, says that the idea of gene-drive moths is something that disturbs him and many others. It "has the potential to disrupt the balance of our ecosystems in ways that cannot be predicted.""This experiment is yet another reminder that gene drive experiments are not safe and ethical," Dana Perls, an environmental group Friends of the Earth, wrote in an email to NPR. We need to halt gene-drivers until there is strong, international, and prudentiary oversight.
