Effect of food deprivation on MCH and GnRH variants in the cichlid fish Cichlasoma dimerus. A morphological and functional study

PÉREZ SIRKIN DANIELA IRINA; CÁNEPA, MAXIMILIANO; FERNANDINO, JI; DELGADÍN TH; FOSSATI, MARIANA; PANDOLFI, MATÍAS; SOMOZA, GM; VISSIO, PAULA

Buenos Aires

Congreso; 7th INTERNATIONAL SYMPOSIUM ON FISH ENDOCRINOLOGY (7ISFE); 2012

International Commitee

In vertebrates, the regulation of appetite is complex and involves the brain and peripheral signals. There are several neuropeptides implicated in the regulation of nutrition and reproduction, suggesting a clear link between feeding and reproductive functions. In particular, both chicken GnRH II (GnRH-II) and MCH have been involved in the regulation of food intake in teleost fish. The main aims of the present study were to examine the effect of fasting over theMCH and the three GnRH variants expression and a possible interaction between these peptides in C. dimerus. We first obtained the full length sequence of the GnRH variants. Then, we studied the effect of fasting by RTqPCR. One-week fasted fish had lower expression levels of both GnRH-II and MCH compared to the fed ones; however, 3 and 4 week fasted fish showed no statistical differences compared to the control group. Concomitantly, by double label immunofluorescence and confocal microscopy we could demonstrate that GnRH-II fibers are in contact with MCH neurons in the NLT. No association was found between MCH and the other GnRH variants. Taken together, these results suggest that GnRH-II and MCH may have an anorexic function in C. dimerus and that there is a functional association between these two neuronal systems.