Factors Influencing Pheromone Release by Male Sea Lamprey.

摘要

Sea lamprey, Petromyzon marinus, rely on chemical communication to synchronize reproduction. Male sea lamprey release a multicomponent sex pheromone comprised of bile acids that attracts females. 3keto-petromyzonol sulfate (3kPZS) is a main component of this pheromone and induces attraction of sexually mature females. In this thesis, I tested the overall hypothesis that pheromone release is influenced by environmental and social factors. Chapter 1 explores the diel patterns in 3kPZS release and behavioral activity, and the mechanisms involved in 3kPZS release patterns. Male sea lamprey releases larger amounts of 3kPZS at night than during the day. Increased biosynthesis of bile acids at night is likely responsible for this pattern. The regulation of 3kPZS synthesis and release helps synchronize behavior and reproduction in sea lamprey. By pairing increased pheromone release to times of increased reproductive behavior, sea lamprey ensure reproductive success. In Chapter 2, the role of male competition on 3kPZS release patterns was investigated. Male sea lamprey immediately increase 3kPZS release after being exposed to various concentrations of 5-deuterated 3kPZS standard ([2H5] 3kPZS, 5d3kPZS), which was used to simulate male competition. This boost in pheromone signaling intensity allows males to compete for mates by potentially matching or exceeding competitors' signals. These studies have advanced our understanding of pheromone communication and its role in sea lamprey. Understanding factors influencing pheromone release can help guide the use of pheromones in an integrated control program for sea lamprey in the Great Lakes.