Researchers are exploring the use of the revolutionary gene-editing tool CRISPR-Cas9 to fight human disease and agricultural blight. But a study from Indiana University has found several challenges to the method’s use in saving lives and crops.
The research, reported today in the journal Science Advances, combines advanced genetic and statistical analyses to show how certain genetic and behavioral qualities in disease-carrying insects, like mosquitoes, make these species resistant to genetic manipulation.
This resistance could complicate attempts to use CRISPR-Cas9 in the fight against malaria—a deadly mosquito-borne disease that threatens over 3 billion people worldwide—or crop blights such as the western corn rootworm, an invasive species that costs the U.S. about $1 billion in lost crops each year.
The discovery of the CRISPR-Cas9 system—or simply “CRISPR”—in the early 2010s introduced an unprecedented level of accuracy in genetic editing. Scientists can use the method to design highly precise genetic “scissors” that snip out and replace specific parts of the genome with sequences of their choosing. Two English scientists were the first to show the method could spread infertility in disease-carrying mosquitoes in late 2015.
“We found that small genetic variation within species—as well as many insects’ tendency to inbreed—can seriously impact the effectiveness of attempts to reduce their numbers using CRISPR technology,” said Michael J. Wade, Distinguished Professor of Biology at IU Bloomington. “Although rare, these naturally occurring genetic variants resistant to CRISPR are enough to halt attempts at population control using genetic technology,…