Natural genetic variation is likely to stymie gene drives, which are designed to deploy specific heritable mutations across a population of organisms, such as disease-carrying insects.
Researchers have recently developed gene drives based on the CRISPR–Cas9 gene-editing system for fruit flies and malaria-transmitting mosquitoes. A team led by Michael Wade at Indiana University in Bloomington modelled whether natural genetic variation in an agricultural pest called the red flour beetle (Tribolium castaneum) could prevent the spread of a CRISPR-based gene drive. The team found that many wild beetle populations harbour genetic variants that, even when rare, would make beetles immune to gene drives that target three different genes.
Inbreeding, which is common in some disease-carrying insects, increases the prevalence of mutations that can inactivate gene drives.