1a. Objectives (from AD-416):
The objective of this proposed project is to characterize proteins (odorant receptors, odorant binding proteins and odorant degrading enzymes), and the gene transcripts that encode them to increase our knowledge of how the codling moth olfactory system works to detect codlemone at the cellular level.
1b. Approach (from AD-416):
1) We will express and characterize proteins predicted to be involved in codlemone detection. This will include odorant binding proteins, nerve membrane receptors, and odorant degrading enzymes. 2) We will determine which odorant binding proteins, nerve membrane receptors, and odorant degrading enzymes are involved in the codlemone signaling pathway using in vitro protein expression and binding assays. 3) We will determine where codlemone reactive proteins are expressed in antennae using fluorescent in situ hybridization and immunofluorescent detection methods. 4) We will determine if codlemone signaling can disrupted using various odorant degrading enzyme inhibitors (many of which are commercially available) in flight tunnel studies.
3. Progress Report:
The work summarized in this progress report relates to objectives number 1 and 2 in the Project Plan for 001-00D: 1. Develop new knowledge of the behavior, genetics, systematic, physiology, ecology, and biochemistry of the insect pests of apple, pear, and cherry, and their natural enemies, that will aid in the discovery, development, and application of management methods and technologies. 2. Identify genes, receptor proteins, and respective ligands that are critical to codling moth development and reproduction. We have identified gene transcripts encoding the major proteins thought to be involved in codling moth pheromone perception and signaling. Gene transcripts encoding these proteins include: pheromone receptors (8), pheromone binding proteins (4), general odorant binding proteins (5), chemosensory proteins (17), odorant degrading enzymes (30), sensory neuron membrane proteins (2), and antennal specific g proteins (2). We have cloned most of these transcripts, and using a cell-based assay have identified a pheromone receptor that binds codlemone (the main sex pheromone that attracts males to females for mating). We have cloned most of the pheromone and general odorant binding proteins, and are currently developing protocols to determine those that bind codlemone. Microplate assays have been developed to monitor detoxification enzyme activities. The results of this research will enable us to develop new compounds which target specific proteins involved in codlemone signaling for more effective codling moth control in the orchard.