**ABSTRACT NOT FOR CITATION WITHOUT AUTHOR PERMISSION. The title, authors, and abstract for this completion report are provided below.  For a copy of the full completion report, please contact the author via e-mail at chungyuw@msu.edu. Questions? Contact the GLFC via email at frp@glfc.org or via telephone at 734-662-3209.**

 

 

SEA LAMPREY PHEROMONES MODULATE LOCOMOTOR RHYTHMICITY

 

Erin J. Walaszczyk1, Yu-Wen Chung-Davidson1, Weiming Li1

 

113 Natural Resources Building, Michigan State University,   East Lansing, MI, 48823

 

February 2016

 

ABSTRACT:

 

All animals are partially controlled by a number of circadian rhythms. These are physical, behavioral, or genetic changes that occur on an approximate 24 hour time cycle and allow the organism to coordinate its internal and external environments. These rhythms are endogenous, but can be affected by external, environmental cues. Sea lamprey offer a unique model to understand locomotor rhythmicity, as throughout their life cycle they switch from a nocturnal rhythm in locomotor activity to arrhythmic multiple times. Adult female sea lamprey respond behaviorally to mature male sex pheromones that guide them to appropriate spawning grounds and induce spawning behaviors. Our overall hypothesis is that locomotor rhythmicity in adult female sea lamprey is modulated by sex pheromone compound. Field tests confirmed that pre-ovulated and ovulated female locomotor activity is affected during exposure to spermiated male washings (SMW), and that in ovulated females SMW can alter the locomotor pattern. The effects of individual SMW compounds were investigated using controlled laboratory studies, and results showed that SMW as well as two components of SMW, 3-keto petromyzonol sulfate (3kPZS) and petromyzonol sulfate (PZS), have differential effects on pre-ovulated and ovulated female locomotor activity. We have also demonstrated that there are effects of these sex pheromones on the GABAergic system in the brain and pineal complex related to neural circuits that guide locomotor activity production. Studies here add to the knowledge of sex pheromone influences on behavior, circadian timekeeping mechanisms, and locomotor activity and rhythm production in this species.  The results here provide further information on how sex pheromones affect adult females in the sea lamprey and how they could contribute to control efforts for this species.