Distinct expression profiles of three melatonin receptors during early development and metamorphosis in the flatfish Solea senegalensis.

Melatonin actions are mediated through G protein-coupled transmembrane receptors. Recently, mt1, mt2, and mel1c melatonin receptors were cloned in the Senegalese sole. Here, their day-night and developmental expressions were analyzed by quantitative PCR.

Melatonin receptors in a pleuronectiform species, Solea senegalensis: Cloning, tissue expression, day-night and seasonal variations.

Melatonin receptors are expressed in neural and peripheral tissues and mediate melatonin actions on the synchronization of circadian and circannual rhythms. In this study we have cloned three melatonin receptor subtypes (MT1, MT2 and Mel1c) in the Senegalese sole and analyzed their central and peripheral tissue distribution. The full-length MT1 (1452 nt), MT2 (1728 nt) and Mel1c (1980 nt) cDNAs encode different proteins of 345, 373, 355 amino acids, respectively.

Cloning and expression of arylalkylamine N-acetyltranferase-2 during early development and metamorphosis in the sole Solea senegalensis.

The arylalkylamine N-acetyltransferase (AANAT) is a key enzyme in the rhythmic production of melatonin. Two Aanats are expressed in teleost fish, one retinal specific, Aanat1, and the other one pineal specific, Aanat2, being the latter the main enzyme responsible of the plasma nocturnal melatonin increase in fish. In anurans melatonin has been involved in metamorphosis through antagonizing thyroid hormone function; however, no available data reports a relationship between melatonin system and metamorphosis in fish.