Document Detail

Effects of different colors of light on melatonin suppression and expression analysis of Aanat1 and melanopsin in the eye of a tropical damselfish.
MedLine Citation:
PMID:  24859252     Owner:  NLM     Status:  Publisher    
Ocular melatonin production exhibits a daily rhythm with a decrease during photophase and an increase during scotophase (nocturnal pattern) in teleost fish due to day-night changes in the activity of the rate-limiting melatonin synthesizing enzyme arylalkylamine N-acetyltransferase (AANAT). Acute light exposure during scotophase suppresses AANAT activity and melatonin production in the eyes, suggesting that external light signals are a principal regulator of ocular melatonin synthesis. To better understand the photic regulation of ocular melatonin synthesis in teleost fish, this study sought to characterize the effect of light on ocular melatonin synthesis in the sapphire devil Chrysiptera cyanea, which shows a nocturnal pattern and light-induced inhibition of ocular melatonin production during scotophase. Exposure to three different wavelengths of light (half-peak bandwidth=435-475nm with a peak of 455nm, 495-565nm with a peak of 530nm, and 607-647nm with a peak of 627nm for the blue, green, and red LEDs) for 2h during scotophase resulted in the blue wavelength significantly decreasing ocular melatonin content within 30min after light exposure. This result clearly indicates that the effective range of visible light on ocular melatonin suppression is distributed within the wavelengths of blue light and that a blue light-sensitive opsin is involved in ocular melatonin suppression in the fish. A PCR-based cloning method revealed the expression of melanopsin, a putative blue light-sensitive nonvisual opsin, in the eyes. Furthermore, in situ hybridization using the sapphire devil Aanat1 and melanopsin RNA probes showed mRNA expressions of both genes in the inner nuclear and ganglion cell layer of the fish retina. These results suggest that melanopsin is a possible candidate photoreceptor involved in ocular melatonin suppression by an external light signal in the sapphire devil.
Yuki Takeuchi; Satoshi Imamura; Yuji Sawada; Sung-Pyo Hur; Akihiro Takemura
Publication Detail:
Type:  JOURNAL ARTICLE     Date:  2014-5-20
Journal Detail:
Title:  General and comparative endocrinology     Volume:  -     ISSN:  1095-6840     ISO Abbreviation:  Gen. Comp. Endocrinol.     Publication Date:  2014 May 
Date Detail:
Created Date:  2014-5-27     Completed Date:  -     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  0370735     Medline TA:  Gen Comp Endocrinol     Country:  -    
Other Details:
Languages:  ENG     Pagination:  -     Citation Subset:  -    
Copyright Information:
Copyright © 2014. Published by Elsevier Inc.
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