Leslie Vosshall, a Howard Hughes Medical Institute investigator at The Rockefeller University will deliver a public lecture titled “Bitten: Why Do Mosquitoes Bite Some People and Not Others?” at HHMI’s Janelia Farm Research Campus in Ashburn, VA.

Vosshall will speak on Wednesday, November 9, 2011, at 7 PM. The lecture, the tenth in a series called “Dialogues of Discovery at Janelia Farm,” is free and open to the public, but tickets are required for admission. Directions for obtaining tickets are available at www.hhmi.org/janelia/events.html. Seating is limited to 250 people.

Vosshall will speak about the cues that mosquitoes use to home in on human hosts. The scent of a human is strongly attractive and this, together with carbon dioxide exhaled in the breath and body heat, guides mosquitoes to their human victims. Only female mosquitoes bite humans and they do this to obtain a blood meal to develop their eggs.

“Understanding why mosquitoes choose to bite particular people may eventually allow us to develop new tools to reduce the spread of deadly mosquito-borne diseases such as malaria, dengue fever, yellow fever, and West Nile fever.”
Leslie B. Vosshall

“Interestingly, while mosquitoes that spread disease to humans prefer humans over any other animal host, not all humans are equally attractive to mosquitoes,” Vosshall says. “Understanding why mosquitoes choose to bite particular people may eventually allow us to develop new tools to reduce the spread of deadly mosquito-borne diseases such as malaria, dengue fever, yellow fever, and West Nile fever.” Vosshall will discuss recent work in the area of understanding the neurobiology of the female mosquito and her research team’s efforts to develop basic scientific knowledge to fight mosquito-borne diseases.

In the 1990s, as a postdoctoral fellow in the lab of Nobel laureate Richard Axel, an HHMI investigator at Columbia University, Vosshall was excited by the series of landmark discoveries that Axel's group was making about the way odors are detected, encoded, and perceived by the olfactory system. Working with Axel, she identified a large family of genes in the fruit fly that function as odor receptors.

As an independent scientist at Rockefeller, she created a nearly complete map of the fruit fly's olfactory system and identified odorant receptors in fruit fly larvae. To the surprise and consternation of many in the field, Vosshall found that insects have evolved a set of smell receptors unlike those found in other animals and humans. Instead of attaching to G protein-coupled receptors, odorant molecules are detected in insects by transmembrane receptors that seem to function as ion channels. (G protein-coupled receptors are a large family of transmembrane receptors that sense molecules outside the cell and activate signaling pathways and other cellular responses inside the cell.)

It has long been known that mosquitoes are attracted to the carbon dioxide that humans exhale, and in 2007, Vosshall identified two membrane proteins in fruit flies and mosquitoes that detect this gas. For the last five years, Vosshall’s team has been studying how insect repellents containing the chemical, DEET, ward off mosquitoes and other bugs. Her lab has recently shown that DEET confuses insects by jamming their odor receptors. Understanding how the chemical works may help researchers develop compounds that are equally effective, but longer-lasting or more convenient to use.

Past speakers in the series have included Sean B. Carroll, HHMI vice president for science education; Thomas R. Cech, former president of HHMI and an HHMI investigator at the University of Colorado, Boulder; Roian Egnor, a fellow at Janelia Farm; Ronald M. Evans, an HHMI investigator at the Salk Institute for Biological Studies; Timothy Harris, director of the Applied Physics and Instrumentation Group at Janelia Farm; Anthony Leonardo, a group leader at Janelia Farm; Gerald M. Rubin, HHMI vice president and executive director of Janelia Farm; Huda Y. Zoghbi, an HHMI investigator at Baylor College of Medicine; Charles S. Zuker, an HHMI investigator at the Columbia University College of Physicians and Surgeons and a senior fellow at Janelia Farm.