Lombardo Francesco, Gioacchini Giorgia, Fabbrocini Adele, Candelma Michela, D'Adamo Raffaele, Giorgini Elisabetta, Carnevali Oliana
Dipartimento di Scienze della Vita e dell'Ambiente, Università Politecnica delle Marche, Via Brecce Bianche, Ancona, Italy.
Consiglio Nazionale delle Ricerche, Istituto di Scienze Marine, UOS Lesina, FG, Italy.
Comp Biochem Physiol A Mol Integr Physiol. 2014 Jun;172:31-8. doi: 10.1016/j.cbpa.2014.02.008. Epub 2014 Feb 15.
The aim of this study was to investigate the melatonin-mediated effects upon the neuroendocrine axis of the brackish killifish (Fundulus heteroclitus), a suitable experimental model to study reproductive events. The ability of melatonin to enhance reproductive capacity (fecundity, embryo survival and hatching rate) inducing the transcriptional activity of gonadotropin releasing hormone (gnrh), luteinizing hormone receptor (lhr) and melatonin receptor (mtnr) was investigated in adult females. Moreover, the melatonin-mediated enhancement of killifish sperm motility and velocity was found consistent with higher fecundity of melatonin-exposed fishes. As a further extent, Fourier Transform Infrared (FT-IR) microspectroscopy evidenced a reduction of lipid unsaturation level on isolated spermatozoa from treated males. Moreover, the reduction of mtnr gene expression during embryo development and lower biometric parameters documented in the larvae from melatonin-exposed parents suggest that melatonin acts as a hormonal mediator able to transfer the environmental signal to oocytes and then to embryos as inheritance of adaptive environmental changes. These results support the positive role of melatonin on killifish reproduction and its role as a maternal factor on embryo and larval development.
本研究的目的是调查褪黑素对半咸水鳉鱼（Fundulus heteroclitus）神经内分泌轴的影响，半咸水鳉鱼是研究生殖事件的合适实验模型。在成年雌性中研究了褪黑素通过诱导促性腺激素释放激素（gnrh）、促黄体生成素受体（lhr）和褪黑素受体（mtnr）的转录活性来提高生殖能力（繁殖力、胚胎存活率和孵化率）的能力。此外，发现褪黑素介导的鳉鱼精子活力和速度的提高与暴露于褪黑素的鱼类更高的繁殖力一致。进一步研究发现，傅里叶变换红外（FT-IR）显微光谱法证明，处理过的雄性分离精子的脂质不饱和水平降低。此外，胚胎发育过程中mtnr基因表达的降低以及暴露于褪黑素的亲本的幼虫中记录的较低生物特征参数表明，褪黑素作为一种激素介质，能够将环境信号传递给卵母细胞，然后传递给胚胎，作为适应性环境变化的遗传。这些结果支持了褪黑素对鳉鱼繁殖的积极作用及其作为胚胎和幼体发育母体因子的作用。
