The Chemistry of Mosquito Sex Could be Key to Controlling Diseases

Researchers at Cornell University have uncovered a chemical ballet that takes place between aedes aegypti mosquitoes during sex. The study, published today in the open-access journal PLoS Neglected Tropical Diseases, found that more than 100 proteins in male sperm permanently alter a female’s tendencies to feed, produce eggs and mate.

The paper’s lead author, Laura Sirot, a research associate at Cornell, did the work in the labs of co-authors Mariana Wolfner, professor of molecular biology and genetics, and Laura Harrington, associate professor of entomology. Sirot, now a assistant professor at the College of Wooster in Wooster, Ohio, also worked with José Ribeiro at the National Institutes of Health.

While previous research by this team identified some reproductive proteins produced in male mosquitoes, “this is the first study to identify the male proteins that are actually transferred to the female” during mating, said Wolfner.

By isolating these proteins, researchers said they may one day develop a birth control approach for female mosquitoes that spread the dengue, yellow fever and West Nile viruses. There is currently no effective treatment for dengue fever, a potentially lethal infection that affects millions of people each year.

The researchers found 93 seminal fluid proteins and 52 sperm proteins in the females. Eventually, researchers might be able to use these proteins to develop innovative mosquito control strategies, such as reducing egg production and curbing the female’s appetite for blood, which could ultimately reduce the spread of mosquito-borne, life-threatening illnesses.

“This is an exciting new avenue for identifying ultimate targets to reduce mosquito vector populations,” said Harrington. “Ultimately, we plan to select the most promising candidate proteins as chemical targets or as a focus for the development of other methods for vector control.”

Next, the team will determine which proteins have major effects on the female’s physiology. In the lab, they plan to generate mosquitoes that fail to make each of these proteins, mate those males with females and observe whether the females’ responses are perturbed.

“By distinguishing between male-derived and female-derived proteins within the female reproductive tract, we can begin to determine which male-derived proteins affect the behavior and physiology of the females, and how they do it,” said Sirot, now an assistant professor of biology at the College of Wooster.

The study was funded by the National Institutes of Allergy and Infectious Diseases within the National Institutes of Health, and from Hatch funds to Harrington and Wolfner.