Cloning and expression of melatonin receptors in the mudskipper Boleophthalmus pectinirostris: Their role in synchronizing its semilunar spawning rhythm
Cloning and expression of melatonin receptors in the mudskipper Boleophthalmus pectinirostris: Their role in synchronizing its semilunar spawning rhythm
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DOI：
10.1016/j.ygcen.2013.11.004
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发表时间：
2014-01-01
影响因子：
2.7
通讯作者：
Chen, Shi Xi
中科院分区：
文献类型：
--
作者：
Hong, Lu Yan;Hong, Wan Shu;Chen, Shi Xi
The mudskipper Boleophthalmus pectinirostris, a burrow-dwelling fish inhabiting intertidal mudflats, spawns only once during the spawning season around either the first or last lunar quarters. To under-stand the molecular mechanisms regulating this semilunar spawning rhythm, we cloned all melatonin receptor subtypes (mtnr1a1.4, mtnr1a1.7, mtnr1b, and mtnr1c). Expression of three melatonin receptor subtypes (except mtnr1c) was found in the ovaries. In contrast, the expression of all receptor subtypes was found in the diencephalon and the pituitary. In the fully-grown follicles, only mtnr1a1.7 mRNA was detected in both the isolated follicle layers and denuded oocytes. Interestingly, the transcript levels of both mtnr1a1.4 in the diencephalon and mtnr1a1.7 in the ovary displayed two cycles within one lunar month, and peaked around the first and last lunar quarters. We used 17 alpha,20 beta-dihydroxy-4-pregnen-3-one (DHP), a maturation-inducing hormone, as a biomarker to examine the involvement of melatonin receptors in the control of the spawning cycle. Melatonin significantly increased the plasma DHP level 1 h post intraperitoneal injection. Melatonin also directly stimulated ovarian fragments in vitro to produce a significantly higher amount of DHP. Taken together, these results provided the first evidence that melatonin receptors were involved in the synchronization of the semilunar spawning rhythm in the female mudskipper by acting through the HPG axis and/or directly on ovarian tissues to stimulate the production of DHP. (C) 2013 Elsevier Inc. All rights reserved.
