Identification, tissue distribution, periprandial expression,and anorexigenic effect of spexin in Siberian sturgeon,Acipenser baeri

摘要

Spexin (Spx), an endogenous peptide, is considered to be a neuropeptide. In a few fish and mammals, it has been proved to play a role in the regulation of animal feeding. However, the possible mechanisms of spexin regulating food intake are mostly blurry in vertebrates including Siberian sturgeon. In this study, firstly, the coding sequence ofspexincDNA was cloned and sequenced in Siberian sturgeon. Then, we detected thatspexinmRNA was widely expressed in the hypothalamus, gastrointestinal tract, and liver, with the highest expression in the hypothalamus. The expression ofspexinmRNA in the hypothalamus was significantly increased after food intake. At 1 h, 3 h, and 6 h after injection, the food intake in the spexin group (0.10, 0.30, and 0.90 mu g/g BW) was significantly lower than that in the saline group. Moreover, compared with the saline group, the mRNA expression of anorecticnucb2,cart,ucn3, andpyyin the hypothalamus was significantly upregulated and orecticnpywas significantly downregulated at 1 h after spexin injection; in the stomach, the mRNA expression ofnucb2andpyywas significantly upregulated. All in all, these results provide evidence for the anorexic effect of spexin on Siberian sturgeon.