Melatonin control of oogenesis and metabolic resources in Zebrafish

P>The aim of this manuscript is to study the effects of two different doses of melatonin (100 nm and 1 mu m) on fecundity in zebrafish females. In addition, an overview of the mechanisms controlling the energy balance and reproduction in fish was provided. At molecular level the expression of cyclo-oxygenase 2A (Cox2A) gene, involved in ovulation control, Leptin and GHrelin, apparently involved in gonadal proliferation and steroidogenesis control, were evaluated by Real Time PCR in class IIIb oocytes. Besides, melatonin role in metabolic resources regulation was here assessed through FT-IR Spectroscopy. Fecundity was positively affected by both doses of exogenous melatonin and the improvement was associated to the increase of Cox2A gene expression. The improvement of fecundity was concomitant with the increase of Leptin gene expression in class IIIb oocyte, the increase was significantly higher only with the higher dose of melatonin, while a significant increase of GHrelin gene expression was found with the lower dose of melatonin. Moreover, a modulation on carbohydrates and lipids metabolism was observed in muscle tissue after melatonin treatment.