Department of Fisheries and Wildlife, Michigan State University, East Lansing, MI 48824, USA.
J Biol Rhythms. 2013 Jun;28(3):218-26. doi: 10.1177/0748730413488994.
Synchronization of male and female locomotor rhythmicity can play a vital role in ensuring reproductive success. Several physiological and environmental factors alter these locomotor rhythms. As sea lamprey, Petromyzon marinus, progress through their life cycle, their locomotor activity rhythm changes multiple times. The goal of this study was to elucidate the activity patterns of adult female sea lamprey during the sexual maturation process and discern the interactions of these patterns with exposure to male pheromones. During these stages, preovulated and ovulated adult females are exposed to sex pheromone compounds, which are released by spermiated males and attract ovulated females to the nest for spawning. The locomotor behavior of adult females was monitored in a natural stream with a passive integrated tag responder system as they matured, and they were exposed to a sex pheromone treatment (spermiated male washings) or a control (prespermiated male washings). Results showed that, dependent on the hour of day, male sex pheromone compounds reduce total activity (p < 0.05) and cause increases in activity during several daytime hours in preovulated and ovulated females. These results are one of the first examples of how sex pheromones modulate a locomotor rhythm in a vertebrate, and they suggest that the interaction between maturity stage and sex pheromone exposure contributes to the differential locomotor rhythms found in adult female sea lamprey. This phenomenon may contribute to the reproductive synchrony of mature adults, thus increasing reproductive success in this species.
雌雄运动节律的同步对于确保繁殖成功起着至关重要的作用。许多生理和环境因素会改变这些运动节律。在美洲鳗鲡（Petromyzon marinus）的生命周期中，其运动活动节律会多次改变。本研究的目的是阐明性成熟过程中成年雌性美洲鳗鲡的活动模式，并发现这些模式与暴露于雄性信息素之间的相互作用。在这些阶段，即将产卵的和已产卵的成年雌性会暴露于性信息素化合物中，这些化合物是由排精雄性释放的，吸引已产卵的雌性到巢中产卵。当成年雌性成熟时，我们使用被动集成标签应答器系统在天然溪流中监测它们的运动行为，并对其进行性信息素处理（排精雄性冲洗液）或对照处理（未排精雄性冲洗液）。结果表明，依赖于一天中的时间，雄性性信息素化合物会减少总活动量（p < 0.05），并导致即将产卵和已产卵的雌性在白天的几个小时内活动增加。这些结果是性信息素在脊椎动物中调节运动节律的首批实例之一，表明成熟阶段和性信息素暴露之间的相互作用有助于成年雌性美洲鳗鲡中存在的不同运动节律。这种现象可能有助于成熟个体的生殖同步，从而提高该物种的繁殖成功率。
