Anopheles gambiae mosquitoFLICKR, NIAID Researchers have eyed gene drives—selfish genetic elements that promote their own inheritance and spread—for controlling populations of disease-carrying mosquitoes. But a new study published last week (October 4) in PLOS Genetics documents a major hurdle: preventing the insects’ evolution to resist the effects of the introduced genetic element.
Tony Nolan of Imperial College London, U.K., and colleagues designed a gene drive that targeted genes involved in egg production to successfully reduce the number of offspring that female Anopheles gambiae mosquitoes produced. The drive included a CRISPR-Cas9–based system to copy the fertility-reducing elements onto homologous chromosomes, so that the gene drive was inherited by nearly all offspring, rather than just half—resulting in its spread through the entire captive population within just four generations. But the insects soon began to evolve mutations that restored fertility and blocked the continued spread of the gene drive.
“Reducing the numbers of mosquito vectors has been the most effective tool to date for the control of malaria, so self-sustaining gene drives designed with this purpose have great potential,” Nolan ...
