Cloning and retinal expression of melatonin receptors in the European sea bass, Dicentrarchus labrax
|Author(s)||Sauzet S1, 2, Besseau L1, 2, Perez P3, Coves Denis4, Chatain Beatrice4, Peyric E1, 2, Boeuf G1, 2, Munoz Cueto J3, Falcon J1, 2|
|Affiliation(s)||1 : Univ Paris 06, UMR7628, Lab Arago, F-66651 Banyuls Sur Mer, France.
2 : CNRS, UMR7628 & GDR2821, F-66651 Banyuls Sur Mer, France.
3 : Univ Cadiz, Fac Ciencias Mar & Ambientales, Dept Biol, E-11510 Puerto Real, Spain.
4 : IFREMER CNRS, GDR2821, Lab Aquaculture Languedoc Roussillon, Stn Aquaculture Expt, F-34250 Palavas Les Flots, France.
|Source||General and Comparative Endocrinology (0016-6480) (Elsevier), 2008-06 , Vol. 157 , N. 2 , P. 186-195|
|WOS© Times Cited||43|
|Keyword(s)||Retina, Melatonin receptors, Sea bass|
|Abstract||Melatonin contributes to synchronizing behaviors and physiological functions to daily and seasonal rhythm in fish. However, no coherent vision emerges because the effects vary with the species, sex, moment of the year or sexual cycle. And, scarce information is available concerning the melatonin age, receptors, which is crucial to our understanding of the role melatonin plays. We report here the full length cloning of three different melatonin receptor subtypes in the sea bass Dicentrarchus labrax, belonging, respectively, to the MT1, MT2 and Mellc subtypes. MT1, the most abundantly expressed, was detected in the central nervous system, retina, and gills. MT2 was detected in the pituitary gland, blood cells and, to a lesser extend, in the optic tectum, diencephalon, liver and retina. Mel1c was mainly expressed in the skin; traces were found in the retina. The cellular sites of MT1 and MT2 expressions were investigated by in situ hybridization in the retina of pigmented and albino fish. The strongest signals were obtained with the MT1 riboprobes. Expression was seen in cells also known to express the enzymes of the melatonin biosynthesis, i.e., in the photoreceptor, inner nuclear and ganglion cell layers. MT1 receptor mRNAs were also abundant in the retinal pigment epithelium. The results are consistent with the idea that melatonin is an autocrine (neural retina) and paracrine (retinal pigment epithelium) regulator of retinal function. The molecular tools provided here will be of valuable interest to further investigate the targets and role of melatonin in nervous and peripheral tissues of fish. (c) 2008 Published by Elsevier Inc.|