In a study published on July 15 in PLoS Pathogens, researchers demonstrate how to genetically alter mosquitoes so they no longer transmit the Plasmodium falciparum parasite, which causes malaria in humans.
Dr. Michael Riehle and colleagues at the University of Arizona, along with partners at UC Davis, have managed to alter the mosquitoes’ genome in such a way that the Plasmodium parasite is no longer able to cause infection when ingested in malaria-infected blood. The authors explain that their genetic modification “acts like a switch that is always set to ‘on,’ leading to the permanent activity of a signaling enzyme called Akt. Akt functions as a messenger molecule in several metabolic functions, including larval development, immune response and lifespan.”
Their original intent was to alter the lifespan or growth rate of mosquitoes (Anopheles stephensi, in this case), and this genetic construct has also been shown to reduce an insect’s lifespan by up to 20%. Most importantly, this altered genetic information is passed on to later generations – if the malaria-resistant mosquitoes can be provided with additional evolutionary advantages and released into the wild (a controversial topic), they could potentially out-perform and eventually replace the malaria-infected wild mosquitoes.
The study has received a wide range of media coverage, including: