Molecular Basis of Pheromonogenesis Regulation in Moths

Abstract

Sexual communication among the vast majority of moths typically involves the synthesis and release of species-specific, multicomponent blends of sex pheromones (types of insect semiochemicals) by females. These compounds are then interpreted by conspecific males as olfactory cues regarding female reproductive readiness and assist in pinpointing the spatial location of emitting females. Studies by multiple groups using different model systems have shown that most sex pheromones are synthesized de novo from acetyl-CoA by functionally specialized cells that comprise the pheromone gland. Although significant progress was made in identifying pheromone components and elucidating their biosynthetic pathways, it wasn’t until the advent of modern molecular approaches and the increased availability of genetic resources that a more complete understanding of the molecular basis underlying pheromonogenesis was developed. Pheromonogenesis is regulated by a neuropeptide termed Pheromone Biosynthesis Activating Neuropeptide (PBAN) that acts on a G protein-coupled receptor expressed at the surface of pheromone gland cells. Activation of the PBAN receptor (PBANR) triggers a signal transduction cascade that utilizes an influx of extracellular Ca²⁺ to drive the concerted action of multiple enzymatic steps (i.e. chain-shortening, desaturation, and fatty acyl reduction) that generate the multicomponent pheromone blends specific to each species.

In this chapter, we provide a brief overview of moth sex pheromones before expanding on the molecular mechanisms regulating pheromonogenesis, and conclude by highlighting recent developments in the literature that disrupt/exploit this critical pathway.