The release of mosquitoes that are resistant to infection with malaria is an interesting idea as a potential control strategy. Research workers at the Johns Hopkins University in Baltimore Maryland provide interesting results suggesting that genetic resistance to the malaria parasite gives mosquitoes feeding on infected blood a fitness advantage. They put 250 transgenic and 250 wild-type mosquitoes of opposite sexes into a cage, where they fed on mice infected with the Plasmodium berghei parasite. The transgene, which blocks infection through the mosquitoes’ gut was found in around 70% of the mosquito population after 10 or so breeding cycles. The prevalence rate of Plasmodium in mosquitoes in nature is usually quite low, nevertheless this work suggests that the transgene could persist in populations.
Transgenic malaria-resistant mosquitoes have a fitness advantage when feeding on Plasmodium-infected blood. M. T. Marrelli, C. Li, J. L. Rasgon, & M. Jacobs-Lorena. Proc. Natl Acad. Sci., 104 . 5580 – 5583 (2007).