Walton D. Jones

B.S., Eastern Nazarene College
Insect Host Seeking: Investigations into the Molecular Mechanisms of Chemosensation
presented by Leslie B. Vosshall

Walton Jones is from Kansas. But as a student in the Tri-Institutional M.D.-Ph.D. Program, Walt provided insight into an important public health problem affecting people far from home: How are blood-feeding insects able to detect minute quantities of carbon dioxide (CO2) given off by a human host standing many yards upwind? The person sitting next to you is exhaling about four percent CO2 into the air, and yet you and all other humans are entirely insensitive to such concentrations of CO2. For a mosquito, even 50 times less CO2 is a loud and clear signal that dinner is nearby.

Working in the fruit fly, Walt identified two proteins, Gr21a and Gr63a, that together form a molecular receptor for CO2. Closely related genes exist in the malaria mosquito and Walt showed that these genes are in the right place to function as CO2 receptors in the mosquito. By searching through 300,000 flies, Walt found a single fly missing Gr63a. It and all its children are completely insensitive to CO2, providing the critical evidence that this protein is part of the insect CO2 receptor. News stories in Scientific American, Nature, Science and the BBC World Service accompanied the publication of Walt’s paper in the journal Nature. We hope that Walt’s discovery will one day translate to better insect repellents that will reduce mosquito bites and thereby reduce the transmission of malaria.

Walt’s father, who did missionary work in Kenya, must surely be particularly proud of this work. Next year, Walt will finish medical school. This year, Walt lives in Seoul, South Korea with his wife Young, improving his Korean language skills. This makes sense because in addition to being a very hard-working graduate student, Walt is also a good son-in-law. The only days he would reliably be away from the lab were the two days leading up to Valentine’s Day, Mother’s Day, Thanksgiving and Christmas, when he pitched in to prepare and sell flower arrangements in his in-laws’ store in the Bronx.