Since insecticides are the most prevalent way of controlling crop damage from pests, their overuse has rendered pests insecticide-resistant. Vector controllers must use toxic compounds when beetles or moths develop mutations that make them resistant to insecticides.
Increased use of these compounds can kill ecologically significant insects and pests. This poses serious risks to health, and damages the environment.
Geneticists from the University of California San Diego developed eDrive, a CRISPR gene-drive system, to combat these problems. The e-Drive genetically modifies the insecticide-resistant genes and replaces them with pesticide-susceptible genes.
The new system uses alleles to replace mutated genetic variations. The researchers have engineered it to disappear later and leave behind the “wild-type” original version of the gene.
Image via University of California San Diego
Ethan Bier is the lead author.Our approach is a biological one that reverses insecticide resistance efficiently without causing any environmental disturbance. The e-Drive has been programmed to temporarily act and then vanish from the population.”
Researchers created a “genetic cassette,” or a new group of DNA components, according to a study published by Nature Communications. They then inserted the genetic “cassette” into fruit flies. It was merely a demonstration of how this technology can be used to treat other insects.
The eDrive cassette is designed to target a specific gene called the Voltage gated sodium-ion channels You can also find out more about VgscThe cassette binds to Cas9 DNA protein and penetrates vgsc insecticide resistance gene. The cassette is bound to Cas9 protein in DNA and penetrates the vgsc gene for insecticide resistance. The gene will then be replaced by its natural form.
Researchers assert that when a cassette gene is inserted into a target insect, its mating passes the pesticide-susceptible gene to its offspring. Geneticists are able to impose limitations on gene-drive systems that can spread continuously unchecked.
The cassette inserted in the X chromosome, for example, reduces male mating. The result is a reduced number of offspring. The cassette frequency in the population will eventually decrease and then disappear.
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Researchers successfully converted native gene in lab results within 8-10 generations.
Image via University of California San Diego
“Because insects carrying the gene cassette are penalized with a severe fitness cost, the element is rapidly eliminated from the population, lasting only as long as it takes to convert 100 percent of the insecticide-resistant forms of the target gene back to wild-type,Ankush Auradkar:
The researchers have stated that due to the e-Drive’s self-eliminating properties, it is suitable for re-introduction as needed. The team also claimed that the e-Drive could be used as a tool to reduce the spread of mosquitos which can transmit disease.
Journal Reference
- Auradkar, A., Corder, R. M., Marshall, J. M., & Bier, E. (2024). Self-eliminating allele-drives reverse insecticide resistance, leaving no transgenes in Drosophila populations. Nature Communications 15(1): 1-10. DOI: 10.1038/s41467-024-54210-4
