Genetically Modified Mosquitoes Could Wipe Out Malaria

Jun 14, 2014

By Alexandra Sifferlin

 

Scientists have figured out a way to modify malaria-carrying mosquitos so they only produce males

After six years of trying, scientists have discovered a way to genetically modify mosquitoes so they produce sperm that will only conceive male offspring.

Female mosquitoes are the ones who bite people and pass along malaria, so scientists think if they can significantly lower the number of female mosquitoes the rate of malaria will also go down. In their research published in the journal Nature Communications, the researchers created a modified strain of mosquitoes that produced 95% male offspring.

3 comments on “Genetically Modified Mosquitoes Could Wipe Out Malaria

  • One thing that this article doesn’t mention, but which is important to this and earlier methods of reducing local Anopheles mosquito populations, is that females mate only once in their lives. Suppose these modified males mated with all the females in a population (and producing enormous numbers of these males in a lab would ensure this was almost true). The next generation’s size would not be enlarged by the injection of extra males into the current one, so the next generation will have 10 times fewer females (5 females per 95 males instead of 50-50). This in turn makes the generation after that 10 times smaller than it would otherwise be, and so on. And while natural selection might throw some spanners in the works, a factor of up to 10 per generation working against it will be hard to overcome. No wonder 4 of the 5 tested populations were wiped out by this trick.

    An earlier method, again relying on producing large numbers of males in the lab, focused on making sure the males were sterilised. This meant hardly any females bore offspring, which reduced the next generation’s size. But this does not create an exponential decline in the population unless the release of sterile males continues (although exponentially fewer would be needed per generation to maintain an exponential decline by that method). I wonder also whether meiotic drive could wipe out local Anopheles populations the way it often does in local mice species. No doubt the experts in the fight against malaria have already looked in to that.



    Report abuse

  • What about the toads that eat those mosquitoes, and the birds that eat those toads, and the mammals that eat those birds, and the humans that eat those mammals…

    We have not heard the end of it.



    Report abuse

  • Ornicar Jun 19, 2014 at 5:33 am

    What about the toads that eat those mosquitoes, and the birds that eat those toads, and the mammals that eat those birds, and the humans that eat those mammals…

    Although many birds eat mosquitoes, one of the key predators is fish. That is why ponds (isolated from rivers) which are left by illegal miners are a dangerous breeding ground for the aquatic larvae of mosquitoes when fish are absent.
    As insecticides usually also kill fish, which take a lot longer than mosquitoes to re-establish, they are frequently inappropriate.



    Report abuse

Leave a Reply

View our comment policy.