Chemical communication in a post-genomic world

With genome sequences accumulating at a rapid pace, one major goal of biology is to understand the function of genes. Many gene functions are comprehensible only within the context of chemical communication, and emerging research on genomics and chemical communication has catalyzed development of this highly productive interface. Many of the most abundantly represented genes in the genomes characterized to date encode proteins mediating interactions among organisms, including odorant receptors and binding proteins, enzymes involved in biosynthesis of pheromones and toxins, and enzymes catalyzing the detoxification of defense compounds. Chemosensory signaling shares several features irrespective of taxon; components of the vast majority of chemosensory signaling systems include a receptor that interacts with a signal molecule, a signal transducer, an amplifier, and a receiver. Across a wide range of organisms, many of the same classes of molecules perform these functions, even if the precise identity of the molecule in particular systems differs. Genome sequencing projects are bringing these similarities into sharp focus for the first time, particularly in the area of chemical communication.

Determining the molecular underpinnings of the component elements of chemical communication systems in all of their forms has the potential to explain a vast array of ecological and evolutionary phenomena. By the same token, ecologists who elucidate the environmental challenges faced by the organisms are uniquely well equipped to characterize natural ligands for receptors and substrates for enzymes. Thus, partnerships between genome biologists and chemical ecologists can be extremely synergistic. To date, these groups have rarely had opportunities to interact within a single forum. Such interactions are vital given the considerable practical benefits potentially stemming from these studies, including the development of biorational products for agricultural and forest pest management, for disease treatment, and for improving the quality of ecosystem health (1).

In 1994, the National Academy of Sciences sponsored a colloquium on chemical ecology; that colloquium, the proceedings of which were published in PNAS, resulted in the publication of a book edited by Thomas Eisner and Jerrold Meinwald, and generated considerable interest in and excitement about the field (2). Since that time, with the availability of genomic tools, the field has metamorphosed and progressed in unprecedented quantum leaps. We organized this Arthur M. Sackler colloquium, held almost a decade later, to aid in the effort to integrate chemical ecology into the broader context of modern molecular biology. The articles in this volume, representing the proceedings of the colloquium held January 17-19 at the Arnold and Mabel Beckman Center in Irvine, California, provide not only examples of cutting-edge work at the interface between molecular and oganismal biology but also useful perspectives and guidelines for future work in these and other systems. We thank Dr. James Langer, vice president of the National Academy of Sciences, and the Sackler selection committee for providing the resources to support the colloquium; Miriam Glaser Heston, program officer for the colloquium series, for superb logistical support and advice; and Andrew Pillifant and Christina Colosimo of the editorial staff of PNAS for invaluable assistance in assembling this special issue. This volume is dedicated to Drs. Eisner and Meinwald, trailblazers and intellectual leaders in this field.