Israeli Students Devise Way to Get Male Mosquitoes to Kill Their Larvae

 For if you do not let My people go, I will let loose swarms of insects against you and your courtiers and your people and your houses; the houses of the Egyptians, and the very ground they stand on, shall be filled with swarms of insects. Exodus 8:17 (The Israel Bible™)

Mosquitoes are not just annoying insects that buzz in your ear while you’re trying to sleep and bite, producing red spots and causing your skin to itch. Those pesky creatures that suck your blood may serve as airborne carriers of serious diseases from malaria to Zika. They congregate around water, from little puddles to large lakes.

There are some 3,500 mosquito species (the word comes from the Spanish for “little flies.” Beginning life in eggs laid on standing water, they hatch into larvae and then become pupas, finally turning into adults. It’s the female that’s the troublemaker, biting the host and feeding on your blood to gorge itself on protein and iron to produce her eggs. The saliva transferred to the victim keeps the blood running and produces an itchy rash.

By transmitting viral, parasitic diseases, bacterial and other diseases to some 700 million people each year, certain species of mosquitoes annually cause the deaths of several million human beings in Africa, South America, Central America, Mexico, Russia and much of Asia.

Preventing the females from laying their eggs in the water is the best way to prevent their spread, but since covering our water sources in pesticides is not possible, eradication is difficult. Now a team from Ben-Gurion University of the Negev in Beersheba has come up with a genetically engineered solution. Calling themselves the FLYGem team, they have found a way to make the males transfer bacteria to the females to produce a poison that kills mosquito larvae shortly after birth. The team and their advisors have filed a patent on the idea through BGN Technologies, the university’s technology transfer company.

The iGEM Competition – an international team competition to promote synthetic biology held annually in Boston – is a good motivator for getting a group of undergraduate students to brainstorm and then experiment with unique out-of-the-box ideas on a tight one-year deadline. In the past, BGU teams have focused on the problem of plastic waste, on amyotrophic lateral sclerosis (Lou Gehrig disease) other diverse topics. This year’s competition was held at the end of October.

FlyGem decided to tackle the problem of mosquitoes. When the team went over the scientific literature on the subject, they found that previous BGU research had discovered that there is a bacterium in the mosquito’s gut called BTI, which, when activated, produces a poison that kills only mosquito larvae.

The problem was how to get it to the larvae. Infecting female mosquitos was out of the question – it’s illegal to release female mosquitos into the wild in Israel, as it is in most countries, because they’re airborne disease vectors. So, the team was faced with how to get the poison to the larvae through the males. They tweaked the male mosquito’s gut microbiome to express BTI and then sent it on its way to find and mate with the females. The females then put the bacteria on the eggs, and when the larvae are born, most of them die. What’s more, the other larvae eat the dead ones, the team discovered, and then die themselves.

Since the poison comes from the mosquito’s own gut and is only deadly only to other mosquitos, the students believe they have discovered a delivery mechanism that far surpasses current human-orchestrated ones based on pesticides.

Team leader Mey-Tal Banar noted: “After an incredible year, I am a great believer in the project and the product that we will present – a targeted, innovative method that could replace the current methods of global mosquito control. I want to thank the project’s executive team, our advisors and the teaching assistants. Without their guidance and support, we would not have gotten this far. And our thanks to the department and to Ben-Gurion University for the opportunity to participate in this challenging international competition.”

FlyGEM, has already filed a patent request for their unique delivery method

Prof. Lital Alfonta, one of the project’s advisors, added: “The students’ progress over a single year has been impressive and unusual. After a further pilot project in urban areas to test out our method, there is a good chance that this will become humanity’s next biological pest control method. For now, we have focused on a single type of mosquito, Aedes aegypti, [that can spread dengue fever, chikungunya, Zika fever, Mayaro and yellow fever], but we have the ability to target other disease-carrying mosquitoes as well.”