Malaria is a huge problem in many parts of the world. Now we may have a genetically-engineered fungus that may almost manage to eradicate a pest that chemical pesticides never quite could: The Anopheles mosquito. Excerpt:
A fungus – genetically enhanced to produce spider toxin – can rapidly kill huge numbers of the mosquitoes that spread malaria, a study suggests.
Trials, which took place in Burkina Faso, showed mosquito populations collapsed by 99% within 45 days.
The researchers say their aim is not to make the insects extinct but to help stop the spread of malaria.
The disease, which is spread when female mosquitoes drink blood, kills more than 400,000 people per year.
Worldwide, there are about 219 million cases of malaria each year.
Conducting the study, researchers at the University of Maryland in the US – and the IRSS research institute in Burkina Faso – first identified a fungus called Metarhizium pingshaense, which naturally infects the Anopheles mosquitoes that spread malaria.
The next stage was to enhance the fungus. “They’re very malleable, you can genetically engineer them very easily,” Prof Raymond St Leger, from the University of Maryland, told BBC News.
Now, this is a temporary fix, albeit a good one. Why? Because the fungus is only expected to kill 99% of the mosquitoes. That means 1% will be resistant to the fungus. That will likely be due to some genetic quirk; some allele of one or more genes will somehow gift its bearer with a resistance to this fungus. At present it is apparent that the frequency of this allele, which at present would appear to give no survival advantage, is about 1%. But after that operation, the frequency of that allele will be approaching 100%, at least for a while.
That’s how allele frequencies in populations change. That’s how populations evolve. And while this is a great step and will have great benefits to people living in these malaria-ridden areas for a while, it’s just another battle in this biological war.