oxygenThe stillness of the night filled the air, broken by the sharp whine of mosquitoes. These blood-sucking insects that disrupt people’s deep sleep also spread diseases such as dengue, chikungunya, malaria and Zika, which affect millions of people around the world each year.
Given the harmful effects of pesticides on the environment, coupled with the emergence of insecticide-resistant mosquitoes, scientists are looking for alternative, environmentally friendly pest management methods.1,2
Now, researchers have developed a new method of population control in which male insects carrying toxic proteins can poison females that spread the disease during mating.3 The results were published in nature communicationsdescribes a genetic biocontrol approach that provides a fast and effective solution for managing pests.
These methods are not entirely new. In the 1950s, when researchers mated female insects with radioactively sterilized males, they produced no offspring, thus reducing the number of subsequent generations.4 Recently, scientists have spread genetic modifications among insects that reduce the fitness of future generations, causing insect populations to decline.5 Although these methods are promising, they require at least one generation to be effective: Female insects may not produce offspring, but they can continue to spread the infection.6
“As we know from COVID-19, reducing the spread of these diseases as quickly as possible is critical to preventing epidemics,” study author Samuel Beach, a graduate student in the lab of Maciej Maselko, a biologist at Macquarie University, said in a press release. important.
Beach and Marcelko explored whether they could target female insects that spread the disease. Other researchers have previously used proteins in male semen to reduce the health and fertility of female partners.7 This physiological response is caused by semen proteins produced by the male’s accessory glands, which are transferred to the female along with the sperm during mating.
Based on these data, the researchers set out to identify proteins that were toxic only to female insects and had no effect on mammals. Using libraries such as FlyAtlas 2, the researchers narrowed down a number of insect-specific venom proteins from spiders and sea anemones.8
Beach and Maselko used flies Drosophila melanogaster A proof of concept testing a method they call Toxic Male Technology (TMT). They genetically modified male fruit flies to produce insecticidal proteins in their reproductive tracts (TMT males). Researchers investigated how the expression of toxic proteins affects the lifespan of male fruit flies. While male flies carrying spider venom proteins lived as long as wild-type flies, male flies carrying sea anemone venom proteins lived shorter. However, courtship experiments showed that expressing these venom proteins did not alter the ability of male flies to court females.
Encouraged by these results, the researchers mated TMT male fruit flies carrying spider venom or sea anemone venom with female fruit flies. Lifespan assays revealed that females mated to TMT males had significantly shorter lifespans compared with females mated to wild-type males.
The researchers next sought to evaluate how this genetic biocontrol approach compared to currently used pest control technologies. They developed computer models to simulate traditional interventions and TMT to predict their ability to suppress populations Aedes aegyptia mosquito that spreads dengue and Zika fever. This model predicts that applying the new method could significantly reduce blood-sucking rates compared to traditional techniques, thereby reducing disease transmission.
While this shows that applying TMT to mosquitoes is possible, the researchers note that this needs to be tested thoroughly. “We still need to implement it in mosquitoes and conduct rigorous safety testing to ensure there is no risk to humans or other non-target species,” Maselko said.
