For the first time, scientists have found a way to turn a fruit fly into a surrogate mosquito, able to carry malaria and infect chickens with the deadly disease. Their approach, reported in the June 30 issue of Science, may pave the way for better anti-malarial, transmission-blocking vaccines, and engineered mosquitoes that are resistant to malaria.
Malaria remains one of the most devastating public health menaces in the world today, killing more than 1 million people a year. Nevertheless, scientists know very little about how mosquitoes carry the disease and transmit it from person to person, largely because the insects are difficult to manipulate and are not conducive to laboratory studies.
"Fruit flies, on the other hand, are a geneticist's best friend. There are many genetic markers, we can conduct genetic screens simply and in large numbers, and we now have the complete sequence of the fly genome," says David Schneider, a Fellow at the Whitehead Institute and the lead author of the study.
These characteristics have made the fruit fly an excellent model to study human diseases, but Schneider suspected that it would also make an ideal model mosquito.
Schneider tested this hypothesis in collaboration with Mohammed Shahabuddin, of the National Institute of Allergy and Infectious Disease. Schneider injected a form of Plasmodium, the parasite that causes malaria in chickens, into the body cavity of the flies. When he allowed the carrier flies to infect chickens, the birds developed full-blown malaria. He also observed that a component of the fly's immune system, known as a macrophage, was able to destroy Plasmodia in an attempt to fight the infection. These results suggest that the fruit fly can indeed serve as a model for studying malaria parasite development.
In carrying malaria, mosquitoes do not act merely as dirty hypodermic needles, passing infected blood from one person to another. Instead, they provide an environment for the parasit
Contact: Stefanie Doebler
Whitehead Institute for Biomedical Research