Endogenous control of circadian rhythms of pheromone production in the turnip moth,agrotis segetum

摘要

The circadian variation of phenomone productionin the turnip moth,Agrotis segetum,was characterized by quantifying (Z)-7-dodecenyl acetate (Z7-12:OAc),the most abundant pheromone component produced by female turnip moth,at different times of day.Under 17:7h hight-dark cycle (LD),the peak of Z7-12:0Ac production occurred around 4h into the scotophose,while these was very little phenomone production during the photophase.When females were maintained under constant darkness(DD),the periodicity of pheromone production was sustained for 3 consecutive days.Furthermore,the rhythm in pheromone production could be entrained to a shifted LD.These results demonstrate that the pheromone production inthe turnip moth in regulated endogenously by a circadian clock.To understand how the circadian rhythm of phenomone productions in generated,circadian variationof phenomone-biosynthesis-activating neuropeptide (PBAN)-like activity in the brain-suboesophageal ganglion complexes (Br-SOG),hemolymph,and ventral nerve cord (VNC) was also examined.Under both LD and DD,only the VNC displayed a circadian variation in the PBAN-like activity,which was significantly higher during the late-photophase than that in the scotophase.In addition,the present study showed that removal of VNC in isolated abdomen did not affect PBAN stimulation of pheromone prudction,while svering the VNC impaired normal pheromone production.The role of Br-SOG,VNC,and hemolymph inthe regulation of the periodicity of pheromone is discussed.