Molecular cloning, expression and appetite regulation function of adiponectin in Siberian sturgeon (Acipenser baerii)

Adiponectin (AdipoQ) as an adipocytokine has the potential to regulate feeding behavior, but the information about adipoq in fish is limited. In this study, Siberian sturgeon adiponectin (Ssadipoq) gene was cloned encoding 264 amino acids. The amino acid identity of SsAdipoQ was low compared with that of mammals, birds, amphibians and teleost fishes. The expression of Ssadipoq in the hypothalamus was significantly decreased at 1 h and 3 h post feeding, and increased after 15-day fasting. The mature domain of AdipoQ (fAd) was inserted into expression vector pET32a and successfully expressed in Escherichia coli BL21 (DE3) after stimulated by isopropyl-β-d-thiogalactoside. Food intake at 1 h and 3 h post treatment with SsfAd protein decreased significantly (P < 0.05). The mRNA expression of pyy and cck in the valvula intestine was promoted and hypothalamic npy, agrp and pomc mRNA expression were inhibited after treatment with SsfAd protein. Furthermore, hypothalamic ampk subunits expression was associated with peripheral SsfAd treatment. In summary, present study indicate that SsfAd plays an important role in the regulation of food intake and appetite signals in Siberian sturgeon, which provides a basis for further study application of prokaryotic AdipoQ in feeding behavior regulation.