Scientists have developed a new method to contain the spread of mosquito-borne diseases like dengue, yellow fever, and Zika by making male mosquitoes deaf, particularly targeting Aedes aegypti mosquitoes, which transmit viruses to around 400 million people per year.
A team from the University of California studied Aedes aegypti mosquitoes, which annually infect approximately 400 million people. Researchers made male Aedes aegypti mosquitoes deaf so that it would be harder for them to mate and reproduce. They observed that mosquito mating can last from a few seconds to nearly a minute. According to scientists, mosquitoes establish sexual relations while flying in the air, relying heavily on auditory cues for mating.
Male mosquitoes rely on hearing to locate females based on their attractive wingbeats. In the mutated Aedes aegypti mosquitoes, the neurons normally involved in sound detection did not respond to the flight tones or wing beats of potential mates. As a result, male mosquitoes were deaf to the attractive sounds of female mosquitoes.
The researchers conducted an experiment that disrupted the hearing of male mosquitoes, causing them to struggle to mate and breed, with the mating of the deaf male Aedes aegypti mosquitoes completely eliminated. The genetic alteration caused male mosquitoes to make no physical contact with females, even after three days in the same cage. In contrast, wild-type (non-mutant) male Aedes aegypti mosquitoes quickly mated multiple times and fertilized almost all the females in their cage.
They focused on a protein called trpVa that is essential for hearing in male mosquitoes. By targeting this protein, they figured out how to disrupt mating using genetics. In the mutated mosquitoes, neurons that usually participate in sound detection showed no response to flight sounds or the wing vibrations of potential mates. The researchers carefully observed mosquito mating, which can last from a few seconds to just under a minute.
Scientists from the University of California, who published their research in the journal PNAS, noted that the effect of the gene knockout was "absolute," as mating of the deaf males was completely stopped.
Dr. Jörg Albert from the University of Oldenburg in Germany, an expert on mosquito mating, commented on the study. He stated, "The study provides the first direct molecular test confirming that hearing is indeed not only important for mosquito reproduction but necessary. Without the ability of males to hear—and acoustically chase—female mosquitoes might become extinct." Dr. Albert added that attacking the hearing of mosquitoes is a promising way to control mosquito reproduction but further research is needed.
Only female mosquitoes transmit diseases to humans. If mosquitoes reproduce less, it will reduce the number of diseases they spread. However, mosquitoes are also an important part of the food chain. Mosquitoes are food for fish, birds, bats, and frogs. Some mosquitoes are important pollinators of plants.
Dr. Jörg Albert also said that the sense of sound in mosquitoes needs to be studied and managed. He added that another method being researched by scientists is the release of sterile males in areas where there are disease outbreaks spread by mosquitoes.
Sources: BBC News, Periódico HOY, ABP
This article was written in collaboration with generative AI company Alchemiq