Genetic approaches are the latest strategy for controlling insects , When controlling mosquitoes that spread malaria, gene drives, which force genetic changes to proliferate in a population, are faster and more efficient than simply releasing mosquitoes that are immune to the parasite, according to a new study.
Genetic approaches are the latest strategy for controlling insects like mosquito populations that spread the malaria parasite and viruses like dengue, chikungunya fever, yellow fever and Zika.
In the lab, scientists have attempted to control the numbers of mosquitoes that can transmit these infections by introducing insects engineered to carry anti-disease genes and through gene drives, where engineered individuals also carry genes that change the rules of inheritance, increasing the odds that the changes passed on and spread throughout the entire population.
In the current study, researchers simulated non-drive and gene-drive mosquito releases using small cage trials to explore the efficacy of delivering anti-malaria genes to a mosquito species that commonly carries the parasite. They demonstrated that both approaches are effective, but the gene drive was more efficient because it needed only a single release of a small number of insects.
In contrast, the non-drive simulation required repeated, larger releases. The drive system targets a gene that affects female mosquito survival after it feeds on blood, and drove mosquito populations to extinction, except in one simulation where mutations popped up that prevented the engineered genes from passed on effectively.
The findings suggest that gene drives will be the most efficient and affordable genetic approach for controlling mosquito populations, assuming that they approved for use in the wild.
The study also demonstrates that preliminary laboratory cage trials can help scientists to test and improve the design of engineered insects before they released. The researchers point out that future gene drive experiments focused on malaria prevention should also involve mosquitoes infected with the parasite to better simulate actual conditions.