Investigating Moth Sex Pheromones
Supported by the BARD Fund US and Israeli scientists have characterized the night-flying moth’s pheromone release system. The researchers anticipate that their interdisciplinary research will generate innovative, specific, and biologically safe insecticide compounds.
Moths, and particularly their caterpillars, are a major agricultural pest in many parts of the world. Sexually receptive female night-flying (i.e., noctuid) moths attract males to mate by releasing a volatile sex-pheromone blend from a gland in the terminal segments of the abdomen. This process is regulated by the “pheromone biosynthesis activating neuropeptide” (PBAN). A group of scientists, supported by the BARD Fund, are investigating how PBAN mediates the release of sex pheromones. Their long-term research goal is to develop a method for inhibiting the release of sex-pheromone in moths, thereby preventing them from mating and, subsequently, destroying crops.
To achieve this goal, the scientists developed a novel binding-assay technique, which they used to identify a membrane-bound protein – the “PBAN receptor” – on the moth gland cells, which mediates PBAN activities. The scientists were the first to identify and characterize such a PBAN receptor in moths. This finding has led to the identification of homolog PBAN receptors in insect species by other laboratories.
Investigating further, the scientists pinpointed the structural elements on the PBAN receptor essential for its function. Interestingly, they found that this receptor is also present in the male moth homologue of the female pheromone gland, and in the nervous system of both sexes.
The scientists also developed a protocol for studying isolated pheromone glands in vitro; a method now employed by many other laboratories. Using this method, they discovered that the PBAN receptor is coupled to another protein, called the “G-protein-coupled receptor” (i.e. GPCR). Furthermore, they showed that this binding induces the entry of calcium ions into the cells, and increases intracellular production of the important cellular molecule “cyclic-AMP.” This discovery represents the first identification of a PBAN-related GPCR that induces pheromone production in the female moth.
This research has provided the scientists with the necessary tools for designing effective and safe insecticides that will specifically block the PBAN-receptorand thereby pheromone production.
The Core Group of Scientists:
- Ada Rafaeli, The Volcani Center, Israel
- Russell Jurenka, Iowa State University, USA