Health & Wellbeing

Genetically-engineered mosquitoes can't transmit malaria

Genetically-engineered mosquit...
Scientists have created genetically-modified mosquitoes that are incapable of spreading malaria
Scientists have created genetically-modified mosquitoes that are incapable of spreading malaria
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Scientists have created genetically-modified mosquitoes that are incapable of spreading malaria
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Scientists have created genetically-modified mosquitoes that are incapable of spreading malaria

Last year, Prof. Anthony James announced that he and his colleagues had genetically altered Aedes aegypti mosquitoes in a fashion that could drastically reduce their populations. In a nutshell, the altered genes cause the female mosquitoes to be born without wings – this makes it rather difficult for them to go foraging for blood, and turns them into easy prey for almost any predator. The non-biting males are born with wings, and subsequently go off and mate with unmodified females, passing the modified genes along to their offspring. Now, James has done some more genetic engineering, to create mosquitoes that can’t spread malaria.

The University of California, Irvine molecular biologist worked with colleagues from both UC Irvine, and the Pasteur Institute in Paris.

They started with mice that were infected with the Plasmodium falciparum parasite, which causes malaria. Those mice created antibodies in order to kill the parasites. The scientists identified the molecular components of this immune response, then altered the genes of the Anopheles stephensi mosquito in order to cause the same response to occur in their bodies – ordinarily, mosquitoes simply act as carriers of the parasites, exhibiting no immune response towards them.

In short, parasites picked up by the mosquitoes are killed by the insects’ altered immune systems, meaning that people subsequently bitten by those mosquitoes won’t develop malaria. Although the study was done using Anopheles stephensi, the technique could reportedly be used on dozens of different types of mosquitoes.

Unlike James’ previous efforts involving the flightless females, this approach would not actually reduce the numbers of mosquitoes present in an area. Much as many people might like the idea of the eradication of mosquitoes, this could be a good thing – it’s still unclear how the sudden elimination of a species as plentiful as the mosquito might affect ecosystems. That said, of course, the wisdom of releasing genetically modified mosquitoes to breed with wild populations might also be questioned.

Given that approximately one million people die worldwide every year from malaria – which is spread mostly by mosquitoes – it’s a risk that some people may be willing to take. “We see a complete deletion of the infectious version of the malaria parasite,” said James. “This blocking process within the insect that carries malaria can help significantly reduce human sickness and death.”

A paper on his research was published this week in the journal Proceedings of the National Academy of Sciences.

Source: University of California, Irvine

16 comments
SteveP
This has been coming for quite a while and is a welcome development. Now to the tricky issue of when they are released into the broader population.
agulesin
Can Prof James modify them so they don't make that annoying whining noise when they're flying? :-)
Billy Sharpstick
As much as I hate mosquitoes, wouldn't this remove one of the largest food supplies of bats?
MintHenryJ
I am not a biology major but think I have a layman's understanding of the "birds and the bees" or in this case mosquitoes. How is it that starving the females does not reduce or eradicate the population? The males don't suck blood so they can't even bring the girls takeout. What do the males eat anyway?
Matt Rings
If this is successful, it's Nobel Prize worthy...
Arf
MintHenryJ, mosquitoes feed on nectar. Females only need a blood meal to produce eggs.
ezeflyer
Releasing GMO organisms into the environment could be extremely risky. In Maine they controlled mosquitoes naturally by releasing drangonflies (mosquito hawks).
Slowburn
Wouldn't it make more since to fix the protein deficiency that requires female mosquitoes to suck blood to lay eggs.
kidsandliz
Of course dramatically reduce the mosquito population and everything that relies on eating them will die off too... so fewer birds, amphibians.. and then those that eat those species will have issues... And if there are other unintended consequences of genetic engineering we might get really good at spreading around a mutated malaria that is worse... Bad idea as much as I'd like to reduce being bitten by the things or have less malaria in the world.
Isabelle
THIS WILL NOT DECREASE THE MOSQUITO POPULATION. Here is the explanation as to why: Normally the males are wingless, and the females fly. Here they are swapping which one has the wings. Just as many males will now fly, as females that they are replacing. But the males do not suck blood. So those males will not be transmitting any disease, regardless. The females will still suck blood, but have the antibodies to kill the malaria, but since they can't fly it isn't a huge help. However, since the males can fly, they can go mate with the non-gmo females that CAN fly, and thus pass on either the trait that swaps who has the wings AND/OR makes them have antibodies, OR BOTH. So even with genetic switching, both traits would be useful. We NEED mosquitos out there in the environment because stuff lives off of them, but it the ones flying around didn't bite people, then it wouldn't matter if there were lots of them. This way we would be able to have lots of mosquitos, and far less Malaria. It would also tip the scales fairly quickly that the males are able to fly to the females because then the genetically altered males will have a higher rate of mating than the non-flying males. This is genius.