Making Insecticides Work Again

Insecticides have been a linchpin of crop production for hundreds of years. But nothing lasts forever, and insects have mutated over time to survive and thrive despite the chemicals.

Resistance has forced farmers to increase the types and amounts of chemicals they use, which isn’t ideal for human health or the environment. 

Enter: Gene-drive technologies. Based on CRISPR gene editing, this tech has the potential to protect crops and decrease the amount of pesticides needed to ward off pests.

This new technology developed by geneticists at the University of California-San Diego is called e-Drive. According to the study, published in Nature Communications, e-Drive “genetically modifies the insecticide-resistant genes and replaces them with pesticide-susceptible genes.”

Soundbite: “We have developed an efficient biological approach to reverse insecticide resistance without creating any other perturbation to the environment. The e-Drive is programmed to act transiently and then disappear from the population.” — Ethan Bier, study author 

Dive in: A small group of DNA elements, or a genetic “cassette” was created and inserted into fruit flies. The cassette spreads through CRISPR gene editing, and eventually the gene is swapped for a native copy that’s susceptible to insecticides. 

When cassette-carrying insects are brought into a target population, they randomly mate, and the e-Drive cassette is passed down to the next generation. The occurrence of the cassette decreases in each generation until it disappears in about 8-10 generations. Because of the self-eliminating nature of e-Drive, it can be introduced and re-introduced as often as needed.

This is kind of a big deal, as researchers are now looking to develop a similar e-Drive system in mosquitoes to lessen the spread of malaria.