Genetically engineered mosquitoes could save millions of lives — or go horribly wrong

The mosquito is, by most definitions, the deadliest creature on the planet.

The small insect causes an outsize amount of pain and suffering by spreading debilitating and potentially deadly illnesses like malaria, which infects around 200 million and kills about 600,000 people a year, and the incredibly painful dengue fever, which infects about 400 million and kills 22,000 a year.

It's no surprise that people want to come up with a way to solve the mosquito problem, and now there's a report that Google wants to get in on the action.

According to a story by The Information, a senior Google executive named Linus Upson wants to "start a biology project involving genetically engineered mosquitoes that would help wipe out other mosquitoes."

As The Information explains, there's not much available information on the project. Their story cites colleagues of Upson — who previously helped build the Chrome browser — who say that he mentioned wanting to start the initiative in order to have a bigger impact, and that he wanted to start the project within Google so he'd be able to work without the pressure of generating a quick financial return.

Google recently announced that the company will spin off their non-search related ventures, like Calico, Fiber, and Google X; those companies and Google itself are now all separate companies under a parent company called Alphabet. A mosquito-eradication initiative could perhaps be a part of the Google X life-sciences group..

How it might work---
While there are no details from Upson or Google about what exactly this possible project might entail, there are two potential ways that scientists have considered using genetically modified mosquitoes to eliminate disease.

One approach that's shown a lot of promise is the release of male mosquitoes that have been engineered in a way that would allow them to seek out female mosquitoes to mate with, as is normal. But because of a defective gene that could be engineered into them, their young wouldn't survive to adulthood.

So far, tests in Brazil and the Cayman Islands have shown that this sort of approach can suppress the population of mosquitoes by 80 to 95% in areas that are vulnerable to a dengue epidemic.

The downside of this strategy is that it would require the constant creation of genetically modified mosquitoes every time the population of normal mosquitoes started to come back, and there would still be some spread of disease, even though the number of infections would be greatly diminished.

The latest genetic editing technology has made another approach possible, one that could totally transform or even eliminate an entire population of mosquitoes. But this approach, which could potentially wipe out an entire species, comes with potentially much scarier side effects.

Entire species manipulation----
The recent discovery of a gene-editing tool called CRISPR makes exact DNA editing easy and cheap, but most importantly here, it makes it possible in the first place — and accurate.

While in general, a person — or a mosquito — has about a 50% chance of getting a particular gene from a parent, there are certain genes that don't follow this rule. As a recent Wired feature explains, there are some genes that manipulate cell division to force themselves to be passed on significantly more frequently.

Researchers are looking at ways to combine CRISPR with these manipulative genes to force the spread of an engineered gene through an entire population. Inserting a particular mutation that gets passed on to all offspring would mean that eventually, all members of a species could have that same engineered gene.

This technique, called "gene drive," provides the power to spread engineered DNA to an entire species. (This wouldn't be used in combination with the technique discussed earlier that kills off mosquitoes before they reproduce, since these are changes that would be passed down from mosquitoes to their offspring — the first technique just stops a certain percentage of mosquitoes from reproducing in the first place.)

Using gene drive, you transform a species by simply releasing a number of newly modified creatures into the wild once — perhaps with a genetic modification that makes mosquitoes unable to carry the malaria parasite. But it could be impossible to stop the spread of that gene if you realized that it was causing some unwanted side effect.

Genetic editing of this sort has not been done in mosquitoes yet, and we don't know if this is the approach that Upson and Google might be interested in. But it has been done in fruit flies, in a lab, and researchers are working on similar mosquito projects already.

Eliminating malaria would be a fantastic result and would save the lives of millions. But we'd want to be certain that we knew exactly what other changes might occur before unleashing these creatures into the wild. If as a side effect, this killed off mosquitoes, that might have effects that ripple through other populations, as mosquitoes are a species that are low on the food chain.

"Once this is out there, you cannot call it back," population geneticist Walter Tabachnick said!

Liveleak on Facebook

Advertisers