Scientists are genetically modifying mosquitoes in a high-security laboratory – and they expect insects to help eliminate some of the mosquito-borne diseases that continue to plague communities around the world.
It is known as a genetic boost: where mosquitoes modified to be incapable of transmitting a particular virus are used to replace the existing population of insects over several generations, with modified genes being passed on to all their offspring.
The idea has attracted controversy because it touches on the fundamentals of nature, but is being considered by the World Health Organization (WHO). This particular test has entered a new phase, reports NPR, with a large-scale release of genetically modified mosquitoes inside a facility in Terni, Italy.
"This really will be an innovative experiment," said entomologist Ruth Mueller, who runs the lab, Rob Stein of NPR. "It's a historic moment, it's very exciting."
Using the CRISPR "molecular scissors" editing technique, a gene known as "doublesex" in bugs was changed. The gene transforms female mosquitoes, taking away their ability to bite and render them infertile.
At the moment, insects are being released in cages designed to replicate their natural environments, with warm, moist air and shelter. Artificial lights are used to simulate sunrise and sunset.
The idea is to see if the mosquitoes with genetic code edited by CRISPR can end the unmodified insects inside the cages. It follows from previous proof-of-concept studies that we saw earlier.
Ultimately, these mosquitoes could be released in malaria-stricken areas, causing the local Mozzie population to fall and save human lives. The disease accounts for more than 400,000 deaths each year – mostly small children.
Reducing these numbers seems like a great idea, so why the controversy? Well, many scientists are asking for caution when it comes to changing the genetic code at this fundamental level – we just do not know the impact that these genetically edited mosquitoes will have on the world around them.
For this reason, the lab is designed to minimize any chance that specially designed mosquitoes may escape. The test was also specifically located in Italy, where this mosquito species – Anopheles gambiae – would not be able to survive outside the natural climate.
"This is a technology where we do not know where this is going to end," said Nnimmo Bassey, director of the Mother Earth Health Foundation in Nigeria. "We need to stop right where it is. They are trying to use Africa as a great laboratory to test risky technologies."
Some experts believe that adding genetically modified mosquitoes to natural ecosystems can harm other plants and animals that depend on them. There are many unknowns.
The team behind the new experiments disputes criticism by saying they are working slowly and methodically – and that the potential side effects are outweighed by the benefits of malaria eradication.
At the moment, scientists are targeting only one mosquito species in the hundreds, and several more years of research and consultation are planned before mosquitoes genetically modified mosquitoes are released.
"There will be concerns about any technology," one researcher, Tony Nolan, of Imperial College London, UK, told NPR.
"But I do not think you should throw away a technology without doing your best to understand your potential to be transformative for medicine, and if it worked, that would be transformative."