Daily variation in melatonin synthesis and arylalkylamine N-acetyltransferase activity in the nematode Caenorhabditis elegans
Version of Record online: 14 OCT 2011
© 2011 John Wiley & Sons A/S
Journal of Pineal Research
Volume 53, Issue 1, pages 38–46, August 2012
How to Cite
Migliori, M. L., Romanowski, A., Simonetta, S. H., Valdez, D., Guido, M. and Golombek, D. A. (2012), Daily variation in melatonin synthesis and arylalkylamine N-acetyltransferase activity in the nematode Caenorhabditis elegans. Journal of Pineal Research, 53: 38–46. doi: 10.1111/j.1600-079X.2011.00969.x
- Issue online: 5 JUL 2012
- Version of Record online: 14 OCT 2011
- Accepted manuscript online: 14 SEP 2011 06:50PM EST
- Received July 1, 2011; Accepted September 9, 2011.
- arylalkylamine N-acetyltransferase;
- N-acetylserotonin methyltransferase;
- Caenorhabditis elegans;
- circadian rhythm;
Abstract: Melatonin influences circadian rhythms and seasonal behavioral changes in vertebrates; it is synthesized from serotonin by N-acetylation by arylalkylamine N-acetyltransferase (AA-NAT) and O-methylation by N-acetylserotonin methyltransferase. However, its physiology and function in invertebrate models are less understood. In this work, we studied daily variations in melatonin synthesis and AA-NAT activity in the nematode Caenorhabditis elegans. Under light–dark conditions (LD), a rhythmic pattern of melatonin levels was observed, with higher levels toward the middle of the night, peaking at zeitgeber time (ZT) 18, and with a minimum value around ZT0-6. AA-NAT activity showed a diurnal and circadian fluctuation with higher levels of activity during the early night, both under LD and constant darkness conditions. A peak was found around ZT12 and circadian time (CT) 12. In addition, we investigated whether this nocturnal AA-NAT activity is inhibited by light. Our results show that both white and blue light pulses significantly inhibited AA-NAT activity at ZT18. This work demonstrates the daily fluctuation of melatonin synthesis and AA-NAT activity in the adult nematode C. elegans. In summary, this study takes additional advantage of an extremely useful invertebrate model system, which has only recently been exploited for circadian studies.