What if Mosquitoes Were Only a Zoo Species?

While environmental organizations are fighting to save animals from extinction, scientists are working for the opposite purpose. They are creating a gene to eradicate species. Genetic engineers are, in fact, developing techniques to kill several types of mosquitoes.

"Half of the global population is at risk of a mosquito-borne disease. They have had an untold impact on human misery" said Frances Hawkes from the Natural Resources Institute at the University of Greenwich. So will mosquitoes become an extinct species we will only see at the zoo?

Only 100 of the 3.500 types of mosquitoes are biting humans. The current outbreaks of Zika virus are spread by the aedes aegypti, which also carries the diseases dengue and the yellow fever. Another well-known mosquito is the anopheles gambiae, which spreads Malaria. While researchers are investigating ways to cure mosquito-born diseases, still the sting of a mosquito leads to death a million people each year.

One of the latest research is using a tool called Crispr/Cas 9 to engineer the DNA of the Aedes aegytpi mosquito. Crispr/Cas 9 is building in a gender switch into the DNA of the mosquito, turning all the offspring into males. Only females bite humans to feed their eggs. When these eggs come out, all the successive generations are males, being unable to reproduce. These genetically modified insects are already successfully tested in smaller experiments, though not ready to fly out of the lab yet.

While this new technique will improve human health drastically, there are still various risks to tackle first. For example, the eradication of a species also influences organisms whitin the same ecosystem. The mosquitoes are  part of a bigger food chain with its own predators, like birds and bads. This gap in the chain can be filled by an even more dangerous species. Besides that, there is a small chance that the modified mosquito gets progeny with another species, passing over the modified genes into a harmless type of animal.

Also our food production is at stake; mosquitoes are pollinators, providing us with vegetables and fruits. Keeping our pollinators alive, like mosquitos, bees and other insects, is high on the agenda of the European Union. On the other hand, with the extinction of one dangerous specie, still thousands of other harmless mosquitos are flying around doing a similar job.

Nowadays we mostly use pesticides to kill mosquitoes and the environmental effects are devastating, such as killing other animals or weakening and polluting ecosystems. At the same time insects get resistant to pesticides. Of course, all forms of prevention become unnecessary if the mosquito would extinct.

Though, the most promising study is done by the Eliminate Dengue Programme. This research puts a bacteria  that fights the dengue virus inside mosquitoes. This technique seems more logic, since it is breaking down the disease instead of the carrier.

It will probably take 10 to 15 years until we will have a big breakthrough in these fields of research. So in a few decennia time we might be able to visit the anopheles gambiae and the aedes aegypti as an almost extinct animal at the zoo, with a sign that says: 'In the past these small animals where one of the most biggest health threats for human kind, but  through genetic modification the lives of many people have been saved'.

Sources: The Wall Street Journal, BBC News Magazine, NY Times. Image: The Wall Street Journal