title: Increased food intake in growth hormone-transgenic common carp (Cyprinus carpio L.) may be mediated by upregulating Agouti-related protein (AgRP).
abstract: In fish, food intake and feeding behavior are crucial for survival, competition, growth and reproduction. Growth hormone (GH)-transgenic common carp exhibit an enhanced growth rate, increased food intake and higher feed conversion rate. However, the underlying molecular mechanisms of feeding regulation in GH-transgenic (TG) fish are not clear. In this study, we observed feeding behavior of TG and non-transgenic (NT) common carp, and analyzed the mRNA expression levels of NPY, AgRP I, orexin, POMC, CCK, and CART I in the hypothalamus and telencephalon after behavioral observation. We detected similar gene expression levels in the hypothalamus of TG and NT common carp, which had been cultured in the field at the same age. Furthermore, we tested the effects of GH on hypothalamus fragments in vitro to confirm our findings. We demonstrated that TG common carp displayed increased food intake and reduced food consumption time, which were associated with a marked increase in hypothalamic AgRP I mRNA expression. Our results suggest that elevated GH levels may influence food intake and feeding behavior by upregulating the hypothalamic orexigenic factor AgRP I in GH-transgenic common carp.
authors.affiliation: State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China; University of Chinese Academy of Sciences, Beijing 100049, China.
authors.forename: Chengrong
authors.initials: C
authors.lastname: Zhong
authors.forename: Yanlong
authors.initials: Y
authors.lastname: Song
authors.forename: Yaping
authors.initials: Y
authors.lastname: Wang
authors.forename: Tanglin
authors.initials: T
authors.lastname: Zhang
authors.forename: Ming
authors.initials: M
authors.lastname: Duan
authors.forename: Yongming
authors.initials: Y
authors.lastname: Li
authors.forename: Lanjie
authors.initials: L
authors.lastname: Liao
authors.forename: Zuoyan
authors.initials: Z
authors.lastname: Zhu
authors.forename: Wei
authors.initials: W
authors.lastname: Hu
mesh_terms: D054369:Agouti-Related Protein / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D030801:Animals, Genetically Modified / Q000235:genetics / Q000378:metabolism; D002347:Carps / Q000235:genetics / Q000378:metabolism*; D004435:Eating / Q000235:genetics / Q000502:physiology*; D013006:Growth Hormone / Q000235:genetics / Q000378:metabolism*
chemical_list: D054369:Agouti-Related Protein; D013006:Growth Hormone
keywords: AgRP; Common carp; Food intake; Growth hormone; NPY; Transgenic