December 10, 2011

Genetically modifying mosquitos to combat malaria. And mosquitos.

Super fascinating article in Gizmag: Genetic genocide: Genetically altered mosquito warriors could wipe out humanity's biggest killer. I never knew this, but mosquitos have killed more than half the humans that ever lived—even more than war, plague, famine, and heart disease. Shocking, no? It's no surprise, therefore, that biotechnologists are starting to think about dealing with mosquitos and the spread of malaria and dengue fever.

The approach would involve genetic hacking, and the solution is really quite elegant:
In short, the modified genes affect only the female mosquitoes, rendering them flightless. The larvae hatch on the water, and the females are unable to leave, rendering them harmless to humans and leaving them to die. The males are unaffected, so they mature normally, then mate with other females to pass the genetic modification on.

It's an extremely effective way of triggering a mosquito population crash - James and his colleagues have proven in cage-based testing in Mexico that a sufficient number of genetically hacked males can completely decimate a mosquito population within a few months. The table below shows this genetic genocide in action - within 23 and 33 weeks, the genetically modified males managed to completely destroy the otherwise stable mosquito population in James' test cages.

A. aegypti eggs make this a fantastically portable solution too - they survive for years at a time in dry conditions, then hatch in the presence of water. So you can more or less post an envelope full of millions of dry eggs to wherever in the world it's needed, and just add water. The crippled females will die where they hatch and you've got yourself a mutant force of GM males ready to start their work.
I also find it interesting to know that there's an open debate about the ecological functionality of mosquitos. It's thought in some circles that mosquitos are a candidate species for selective extinction, and that their absence in the ecosystem would not be disruptive.

Damn, I hope that's true. Could you imagine a world with no mosquitos?

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