Scientists at the University of Maryland have created a genetically modified (GM) fungus that secretes a toxin that kills malaria mosquitoes. The effectiveness of this method to combat carriers of a deadly infection was first tested outside the laboratory. This is reported by Science Alert.
The researchers introduced genes into the fungus Metarhizium pingshaense that encode calcium-activated potassium ion channels and a hybrid hexatoxin-Hv1a. The latter is isolated by the deadly Australian funnel spiders. To test a hybrid fungus pathogenic to Anopheles coluzzii mosquitoes, the Mosquito Sphere, a complex built to simulate the natural environment in Burkina Faso, West Africa, was used. In this region, the incidence of malaria in 2017 was 7.9 million.
The "Mosquito Sphere" consisted of six compartments. Four of them, covered with a greenhouse film, contained buildings with calves, plants for adult mosquitoes, and mating areas. Insecticide-resistant A. coluzzii were collected for the experiment in the form of larvae from natural habitats, and inside the compartments the insects reached their adult form. The fungus was placed on a cloth and hung inside the "sphere".
It turned out that mosquitoes exposed to the fusion protein died 1.6 times faster than from the wild form of M. pingshaense. The insect population died within 45 days. At the same time, fungi are less species-specific than the gene drive method, with the help of which harmful mutations are spread within the most wild population of mosquitoes using GM insects.