1:25 min Read
Planning on hiking this summer? Well, arm yourself with strong mosquito repellent lest swarms of bloodsuckers keep you swatting—or worse.
For populations across the globe, the nuisance of itchy mosquito bites can be just that: a nuisance, not a death sentence. But for others, particularly those living in tropical and subtropical regions, just one bite from a female mosquito puts them at high risk of developing malaria—a life-threatening parasitic disease.
Breeding Safer Mosquitos
According to WHO, there were 229 million malaria cases resulting in 409,000 deaths in 2019. Fortunately gene editing enables scientists to breed mosquitos that are less likely to carry and transmit the disease.
For decades, attempted control measures have produced very limited results. Compounding matters, mosquitos now exhibit a growing resistance to pesticides, while the malaria parasite itself is becoming increasingly resistant to anti-malaria drugs.
But the tides could soon shift in our favor. Innovations like CRISPR-Cas9 gene editing are rapidly opening a new front against disease-bearing mosquitos.
Scientists are building gene drives—so-called "genetic scalpels for DNA"—that can recognize, cut and rearrange strands of the insect's own DNA. Notably, this tool can allow for a particular combination of edited genes—including those that reduce the likelihood of carrying or spreading malaria—to be passed on through the reproductive process of mosquitos to their succeeding generations.
In traditional heredity, the probability that a new gene will be present in offspring is just 50 percent. With a CRISPR-Cas9 gene drive in place, that probability rises to virtually 100 percent. In fact, scientific modeling has demonstrated that the edited, antimalarial gene sequence could be passed to the entire mosquito population in as few as seven generations.
Of course, researchers are proceeding with additional studies on the full ecological and environmental impacts of this gene-drive method of disease control. But the initial results are extremely promising.
The potential exists to eradicate malaria at the source; outsmarting current methods of reactionary treatment. But, for now, you still need to keep the bug spray handy.