Carmel Valley resident discusses recent work on study that shows genetic-based ways to fight malaria

Ethan Bier, a UC San Diego cell and developmental biology professor who lives in Carmel Valley, was part of a study released July 23 that shows genetic-based ways to fight malaria.

The mosquitoes that spread the disease have developed immunity to some of the insecticides that have previously helped reduce the spread, Bier said in an interview. There were nearly 600,000 malaria deaths in 2023, the most recent year that data is available from the World Health Organization, and 263 million cases. Africa accounts for more than 90% of each.

“The hope would be this kind of genetic system can get integrated with existing approaches like using insecticide, impregnated bed mats and spraying the walls inside of homes with long-lasting insecticides, anti-malarial drugs,” Bier said.

He continued, “The hope is to add something like these genetic systems to help in the overall effort.”

Their system uses the CRISPR-Cas9 gene editing method to make a particular change in the mosquito’s genome to discard an amino acid that transmits malaria with another version that doesn’t.

The study, published in the Nature journal, also includes researchers from UC Berkeley and the University of São Paulo.

Bier said his involvement stems from the work his lab has done over the years on fruit flies, focusing on how they develop from a fertilized egg into their final form. He also uses them as a model of the genetic system.

“Many of the genes fruit flies have are actually very similar to humans,” he said.

Then there was collaboration dating back 10 years ago that led to the work on mosquitoes and malaria transmission.

“An excellent graduate student came up with a creative idea in pursuing his work about how it is you make wing veins in a fruit fly, came up with an idea of doing that in distantly related flies,” Bier said. “In trying to do so, he cooked up an idea about how to do it more efficiently, which led to this genetic system that we developed that we now refer to as active genetics where a genetic element that’s located in a certain position in the genome can copy itself to the identical location on another chromosome, and thereby get itself transmitted to a much higher percentage of progeny.”

The goal is to use the work to contribute to existing ways of fighting malaria.

“The beauty of this approach lies in leveraging a naturally occurring mosquito gene allele,” George Dimopoulos, a researcher from Johns Hopkins University who was part of the study, said in a statement in UC San Diego Today. “With a single, precise tweak, we’ve turned it into a powerful shield that blocks multiple malaria parasite species and likely across diverse mosquito species and populations, paving the way for adaptable, real-world strategies to control this disease.”