Survival of the fittest: GM malaria-resistant mosquitoes out compete diseased relatives

A team of researchers announced today that they have genetically modified a species of mosquito resistant to the malaria Plasmodium parasite. And that these GM mosquitoes out compete their relatives because the infected mosquitoes suffer from effects of the disease. Experiments showed that from a population of equal proportions, nine generations after the insects fed off of malaria-infected mice, 70% of the bugs were the malaria-resistant type. This picture shows a GM mosquito, whose eyes glow green because of a second modified gene for green fluorescent protein (GFP).

I have strong beliefs about the genetic modification of foodstuffs because 1) we are casually tinkering with genomes nature spent millions of years fine-tuning - what makes us think we know what we are doing? Some times science has unexpected consequences. And 2) The desirability of ‘superior’ crops and livestock produced through selective breeding and genetic modification have created monocultural populations which are hypersensitive to environmental change and disease.

However, in the case of agriculture, most ‘tinkering’ is uneeded effort; in the case of malaria, a solution could prevent one million deaths each year. Will this disease be controlled by introducing GM insects into wild populations? Not in the near future, but may be someday.

Mauro T. Marrelli, Chaoyang Li, Jason L. Rasgon, and Marcelo Jacobs-Lorena. March 19, 2007. Transgenic malaria-resistant mosquitoes have a fitness advantage when feeding on Plasmodium-infected blood. Proceedings of the National Academy of Sciences.