2005 Prize Winner Dr. Pingxi Xu, M.D., Ph.D. University of Texas Southwestern Medical Center, Dallas

The author of the prize-winning essay "Extracellular LUSH Protein in VA Sensitivity", Pingxi Xu, was born and grew up in the northern province of Jiangsu, China. His first career was as a pediatrician, but after years of pediatric practice, Dr. Xu became interested in exploring basic science. To this end, he returned to university in Xian, China, and in 1988 earned a Master’s degree in biochemistry and in 1999 a Ph.D. in neurobiology. In 2000 he joined Dr. Dean Smith's lab at the University of Texas Southwestern Medical Center in Dallas. Here he worked hard at understanding the molecular basis of pheromone signaling in Drosophila. Dr. Xu's goal is to apply this knowledge to control mosquito breeding by interrupting their perception of pheromones. Although his focus has moved from babies to bugs, his goal remains essentially the same: to improve human health by preventing the occurence and spread of disease.

Extracellular LUSH Protein in VA Sensitivity
Many insects can detect pheromones at near-single molecule sensitivity; however, the mechanisms required to achieve this feat remain vague. The prevalent notion postulates that pheromones are transferred to pheromone receptors on neurons by odorant-binding proteins (OBP).Using genetic methods and electrophysiological recordings on single neurons, we found that a Drosophila OBP termed LUSH is required for perception of an aggregation pheromone. In the absence of LUSH the fly is completely insensitive to pheromones, both behaviorally and electrophysiologically, but an introduction of LUSH can restore function.Surprisingly, the lack of LUSH also leads to a dramatic reduction in spontaneous impulse. These findings suggest that the OBP could be acting as a coligand – mediating pheromone recognition – as opposed to being a simple pheronome transporter.At present, we have identified a handful of OBP-dependent antagonists that can disrupt pheromone transduction. We would further this study in an attempt to understand the mechanism and help design pheromone-behavior disruptants aimed at pest management.

For the full text of the essays by the Prize Winner and Finalists, see Science Online at sciencemag.org.

2005 Finalists
Dr. Justin Blau
Dr. Paul Frankland
Dr. Johanna Montgomery