Celebrated UCD scientist wins lecture award

Walter Leal praised for work on pheromones, personal productivity, collaborations

Walter Leal, professor and chairman of the Department of Entomology at UC Davis, recently received the International Society of Chemical Ecology’s 2007 Silverstein-Simeone Lecture Award for his innovative research on how insects detect smells and communicate within their species.

Leal, a noted chemical ecologist, received the award at the scientific society’s annual conference in Jena, Germany.

University of Munich professor and chemical ecologist Karl-Ernst Kaissling praised Leal’s significant contributions to cutting-edge science, his high productivity and his multidisciplinary collaborations.

Over the last two decades, Leal has identified and synthesized complex pheromones from many insects, including scarab beetles, true bugs, longhorn beetles and moths.

Pheromones are chemical signals released to attract other members of the species.

Leal discovered a sophisticated mechanism for the isolation of the chemical communication channels of two species of scarab beetles in Japan. More recently, Leal and UC Davis researcher Yuko Ishida isolated, cloned and expressed a pheromone-degrading enzyme from the wild silkmoth, Antheraea polyphemus.

Leal is also noted for his discovery of the pheromone-binding protein of the silkworm moth, Bombyx mori.

Methods that can attract or repel insects have important applications for agricultural pests and medical entomology. The research could lead to designing better chemicals to attract insects and designing better chemicals to suppress insect communication.

In introductory comments, Kaissling pointed out that over the last 20 years, Leal has authored or co-authored more than 130 scientific papers and written some 20 invited chapters and review articles.

“In the titles of these papers you find about 30 names of new pheromonal compounds, and 60 animal species – many mites and insects,” he said.

“One of the highlights of the last 10 years are – for me – the papers on the pheromone-binding protein of Bombyx mori (silkworm moth),” Kaissling said. Leal collaborated with structural biologist Jon Clardy, then at Cornel University, and Nobel laureate Kurt Wuthrich, a nuclear magnetic resonance scientist with ETH Zurich.

Leal studies the binding kinetics of protein and pheromone “which helps us to better understand what happens in the olfactory sensilla,” Kaissling said. An insect senses smells on the hair-like sensilla in its antenna.

“Another exciting achievement is the recent expression of the bombykol receptor in the empty olfactory neuron of Drosophila (fruit fly),” Kaissling said.

Leal, a past president of ISCE, joined the UC Davis faculty in 2000. A former chemical engineer in his native Brazil, Leal received his master’s degree in agricultural chemistry from Mie University, Japan and his doctorate in applied biochemistry from the University of Tsukuba, Japan.

He later served as research leader of the Science and Technology Agency of Japan and the Bio-Oriented Technology Research Advancement Institute (BRAIN) and head of the Laboratory of Chemical Prospecting at the National Institute of Sericultural and Entomological Sciences in Tsukuba.

Leal won the Technology Prize (Gijitsusho) of the Japan Society for Bioscience, Biotechnology and Agrochemistry in 1994; the Medal of Honor from the Entomological Society of Brazil in 1995; and the Gakkaisho (equivalent to a Fellow) from the Japanese Society of Applied Entomology and Zoology in 1998.

ISCE is a scientific organization that promotes the understanding of interactions between organisms and their environment that are mediated by naturally occurring chemicals. Research areas include the chemistry, biochemistry and function of natural products, their importance at all levels of ecological organization, their evolutionary origin and their practical application.

The ISCE Silverstein-Simeone lecture award, memorializing Robert M. (Milt) Silverstein (1917-2007) and John B. Simeone (1919-2005), founding editors of the Journal of Chemical Ecology, recognizes outstanding recent or current work at the frontiers of chemical ecology, rather than longterm career achievement.

The 2007 Silverstein-Simeone lecture was the first since Silverstein’s passing on Feb. 26 at age 90. Leal paid tribute to him by observing a moment of silence, and then interviewed two chemical ecology icons about Silverstein’s contributions to the field: Jerrold Meinwald of Cornell University and David Wood of UC Berkeley. Meinwald served on the search committee when the State University of Syracuse hired Silverstein, and Wood was his major collaborator.

DailyDemocrat