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STRUCTURE AND FUNCTION OF SEA LAMPREY PHEROMONE COMPONENTS (PHASE II)
1 Michigan State University, Department of Fisheries & Wildlife, email@example.com, firstname.lastname@example.org, email@example.com
2 University of Michigan, Graham Sustainability Institute, firstname.lastname@example.org
3Texas State University, Department of Biology, email@example.com
The complex pheromone communication system employed by lamprey is essential for its life cycle, making pheromones targets for sea lamprey control. Our overarching objective was to characterize the structures and functions of candidate pheromone components released by larvae and sexually mature males. Several novel tetrahydrofuran-diol lipids were isolated from larval washings and subsequently tested on migratory adults. One compound, (+)-PMA is the first compound tested that replicates larval washings in biasing migratory adults into a stream channel. We isolated eight novel sulfated steroid compounds from mature male washings; five were significantly attractive and one significantly repulsive to ovulated females in a two-choice maze. However, these were never tested using in-stream assays, so more detailed behavioral responses were not characterized. Two additional sulfated steroid compounds DkPES and PAMS-24 were shown to act as proximity pheromones that influence female behavior near an odor source. Our results also indicate PAMS-24 may act as a territorial pheromone for mature males, but we are still evaluating this hypothesis. Multiple advances were also made in our general understanding of the pheromone communication network. We identified females can differentiate a pheromone signal based on sexual context, and that 3kPZS can outweigh temperature in influencing migratory females to move upstream. Additionally, there are multiple factors that influence pheromone release by sexually mature males. Male size, competition, and time of day all have impacts on 3kPZS release and provide insights into evolutionary mechanisms that have shaped the signaling system. Overall, we isolated 18 compounds; 16 were tested for olfactory potency using electro-olfactogram recordings (EOGs), and 14 were tested for behavioral responses using a two-choice maze or in-stream assays.