| Nesfatin-1 and xenin are anorectic peptides cleaved from their precursor proteins nucleobindin-2 (NUCB2) and coatomer protein-a (COPA), respectively. During my MSc thesis research it was found that nesfatin-1 is co-localized with ghrelin, a potent orexigen, in the gut and brain of goldfish. This suggests that nesfatin-1 may interact with ghrelin to regulate food intake of goldfish. In support of this, intracerebroventricular administration of gfnesfatin-1 or gfghrelin, suppressed preproghrelin and NUCB2 mRNA expression in the gut and brain of unfed fish, 1 h post-injection. These results suggest that nesfatin-1 suppresses ghrelin to induce satiety. In addition, I characterized xenin as a novel anorexigen in goldfish. Using a human COPA antibody, xenin-like-ir is present in the gut and brain of goldfish. Both intraperitoneal and intracerebroventricular administration of xenin reduced food intake in goldfish. Together, my thesis research provides novel evidence for nesfatin-ghrelin interactions, and the anorectic functions of xenin in fish. |
