Genetically Modified Mosquitoes: What Are They All About?

Illustration by Joseph Laney.

For many people, summer is a time people look forward to. It's the season of the beach, picnics, and unfortunately, mosquitoes. These insects are such a nuisance that you've probably thought to yourself, "why don't we just eradicate them from the planet?" or possibly even "why don't we change them so that they don't drink human blood?" Well, biologists have thought about this question too, so let's talk about the causes and effects of genetic modification.

Mosquitoes are vectors for thousands of diseases, including malaria, Chikungunya, Encephalitis, West Nile virus, Zika virus, yellow fever, and dengue fever. All of these are still known to be fatally dangerous to humans around the world. With the discovery of CRISPR-Cas-9 technology in 2012, the risk of contracting such diseases has been rapidly decreasing. Genetic modification is an ultimately more viable and preferable alternative to the eradication of mosquitoes that allows for the selective change of genes that contribute to the passing on of disease.

Various people affected by Chikungunya virus, Mayo Clinic Proceedings.

An infant affected by Zika virus, Antonio Lacerda.

In a study, Research Associates at Imperial College genetically modified the malaria-transmitting mosquito Anopheles gambiae. They used CRISPR-Cas9 technology to insert a gene that encodes an antimalarial protein amidst genes that are turned on after the mosquito eats a blood meal. The team bred the mosquitoes to see if they could reproduce successfully and stay healthy. Additionally, The biotechnology firm Oxitech released male mosquitoes in the Florida Keys engineered to carry a deadly gene that causes their female offspring to die before reaching maturity. Since only female mosquitoes bite animals and people, the modified mosquitoes and their surviving male offspring cannot pass on disease.

The goal of most modification is to reduce the risk of contracting mosquito-borne illnesses without killing them all. Over 3,500 species of mosquito have been discovered, and mosquitoes are an integral part of our ecosystem; they are pollinators, which is extremely important due to the decline of the honey bee population, and they are a source of food for several animals. The release of the modified mosquitoes in Florida sparked controversy among residents because they simply did not want to see anything genetically engineered in their environment. As an emotional response, this makes sense since they did not make the decision to let the changed insects loose. Not only are locals scared that they might be effected by them, but they are worried that more harmful insects will fill in the void left by mosquitoes in the ecosystem. The scientists conducting the research have not well-studied the environmental risks of genetically modifying mosquitoes, but this is expected to be researched with these clinical trials in Florida.

The city of Douala, Emiliano Gandolfi.

Personally, I admire mosquitoes as a valuable part of our ecosystem and find research studies such as those done by Oxitech very admirable. My dad grew up in Cameroon, a West African country, and has had malaria more times than he can remember. He was extremely ill for all those times, and my mom has also been sick from the virus. Furthermore, he lived in the densely-populated city of Douala for a time, which is  a breeding hotspot. As travelers may know, the vaccine for malaria can also induce sickness comparable to the virus itself. When I needed to be vaccinated for my trip to Cameroon, I experiences nightmares and cold sweats, and I never even got malaris. I believe that genetic modification is a fantastically ground-breaking solution to mosquito borne illnesses and the ailments that come along with it.