GMMs: Genetically Modified Mosquitos

Wednesday, July 11, 2012

Mosquito feeding (eyeweed on flick/flickr)

When we think of death and destruction, our minds likely fill with images of fires, tsunamis, car accidents, and nuclear disasters. But in fact, the deadliest threat to the human race is none of these things. As Michael Specter writes in his new article for the New Yorker, “mosquitoes have been responsible for half the deaths in human history.” Malaria, a disease spread by the Anopheles mosquito, caused up to one million deaths in Africa in 2008. 

Up until now, our main ways of combating mosquitoes involved avoidance and swatting. But a British company is trying something different: the genetic modification of the mosquitoes themselves.

Biotechnology company Oxitec has developed a method to modify the genetic structure of the Aedes aegypti mosquito, essentially transforming it into a mutant capable of destroying its own species. Eggs fertilized by genetically modified males will hatch normally, but soon after, and well before the new mosquitoes can fly, the fatal genes prevail, killing them all. The Aedes mosquito is responsible for Dengue fever, a disease that infects 50-60 million people each year, as well as yellow fever.

"[Dengue] is a tremendous beneficiary of globalization," Specter says. One of the favorite breeding grounds for Aedes aegypti mosquitos is the inside of an automobile tire, of which there are billions exported around the world. 

Specter sees this new aggressive attempt to kill off mosquitoes as an excellent way to disrupt the species and bring down the number of Dengue infections. "The result would be that the more you mate these lab-bred mosquitos with wild females, the more the eggs would be impotent and die, and not be able to carry Dengue," Specter says. Nicknamed "break-bone fever," the disease causes extreme pain, does not have a cure, and kills thousands of people every year. 

One of the risks of genetically modifying plants or animals is a potential disruption of the food chain, which could bring unforeseen consequences down the road if the program were implemented on a large scale. However, Specter believes that North and South America would do just fine without the Aedes aegypti, which is originally an invasive species that came over from Africa aboard ships a couple hundred years ago. 

"They could be gone, because that's really not enough time to make an evolutionary impact anywhere," he says. Mark Q. Benedict, an entomologist at the University of Perugia, says “it’s important to remember we’re already trying to wipe this species out, and for good reason. The risk involved in eliminating them is very, very small. The risk in letting them multiply is enormous.”


Michael Specter

Produced by:

Robert Balint and Kristen Meinzer

Comments [5]

Robb Moffett from Surfside

I made a simple mosquito fan trap for a dollar that hooks to a cheap box fan that will eliminate all indoor mosquitoes and if left outside, will over time remove them from the neighborhood. It only costs about a dollar in raw materials if you have a fan. I put the video on how you can easily make my fan trap on youtube.

There is no excuse for you or your family or pets to suffer from mosquitos. You can run a fan all month long for about 2 dollars worth of electricity.

How to make a $1 Homemade Mosquito Bag Fan Trap kills bugs dead

Jul. 13 2012 08:23 AM
Michael L from Key West

Thank you for a great interview. I am looking forward to the article by Mr. Spector. I hope that this will help people become more aware of the real issues involved in eradication of the dengue-carrying mosquitoes. That way we can make our decisions based on facts.

Jul. 12 2012 03:44 PM
Luke Alphey from Oxford

Great interview!
'Angel' raises some interesting questions. The specific mosquito strain and species (Aedes aegypti) in question spread dengue rather than malaria, but the same questions could be asked. To take each in turn:
1) Can dengue itself can mutate to allow another animal as carrier?
There are a couple of other mosquito species that can transmit dengue, though less well - all significant epidemics depend on Aedes aegypti. Of these the best known is Aedes albopictus. Since Aedes albopictus overlaps with Aedes aegypti, and has a wider distribution, there is already strong pressure for the virus to develop the ability to be spread better by albopictus. So this may occur naturally, but the use of these engineered mosquitoes does not add to the risk; one could argue that it somewhat reduces it
2) GMM can develop new strain of Malaria or new disease
These mosquitoes are short-lived and their offspring die. This would make them less able to transmit any disease (plus the released males don't bite). These arguments may not apply to all potential modified mosquitoes though
3) Any pests affected by Malaria can have a population explosion and 4) Any pests carrying a deadlier disease will escape early Malaria death and pass their own infection to humans
Human malaria and dengue are specific to humans (and their mosquito vectors). With reduced childhood mortality, human populations have reduced, rather than increased, their own fertility.
5) GMM can become inedible by its predators which will affect predators' survival; and on and on
The engineered mosquitoes just like normal ones for predators. Furthermore, this (Aedes aegypti) is an alien invasive species, not part of the native ecosystem, though many species will eat them if they find them, none are know to depend on this species

Jul. 12 2012 05:39 AM
Angel from Miami, FL

Wasn't three Jurassic Park movies enough of a message to know we shouldn't tamper with the natural order of things?

Some results quickly come to mind: 1) Malaria itself can mutate to allow another animal as carrier; 2) GMM can develop new strain of Malaria or new disease; 3) Any pests affected by Malaria can have a population explosion; 4) Any pests carrying a deadlier disease will escape early Malaria death and pass their own infection to humans; 5) GMM can become inedible by its predators which will affect predators' survival; and on and on.

Jul. 11 2012 10:51 AM
Manny from Fort lauderdale

I was once told to honor the mosquito because they are the only thing preventing human infestation and devestation of our last standing forests vital for our own survival on this planet. If your just looking looking for a way to enjoy your back yard get one of those mosquito misting systems they work great.

Jul. 11 2012 09:57 AM

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