title: Molecular cloning and functional characterization of spexin in orange-spotted grouper (Epinephelus coioides).
abstract: Spexin is a newly discovered neuropeptide in vertebrates. Comprehensive comparative studies are required to unveil its biological functions. In order to ascertain the neuroendocrine function of spexin in orange-spotted grouper, its full-length cDNA and genomic DNA sequences were cloned and analyzed. Sequence analyses showed that the spexin gene structure is composed of six exons and five introns, and the amino acids of mature peptide (spexin-14) in grouper are identical to that of other fish. Tissue expression analysis found that grouper spexin is highly expressed in the brain, liver and ovary. Real time-PCR analysis demonstrated that the hypothalamic expression of spexin declined gradually during the ovarian development, and was up-regulated by food deprivation. Intraperitoneal administration of spexin-14 peptides to grouper significantly elevated the mRNA levels of proopiomelanocortin (pomc) and suppressed the orexin expression in the hypothalamus, but could not change the hypothalamic expression of gonadotropin releasing hormone 1 (gnrh1). Both in vivo and in vitro administration of spexin could not significantly influence the expression of follicle-stimulating hormone β (fshβ) and luteinizing hormone β (lhβ) in the pituitary with the exception of an inhibition of gh expression. Our data suggested that the spexin has a significant role in the regulation of energy metabolism and food intake in orange-spotted grouper.
authors.affiliation: Zhanjiang City State Key Laboratory of Marine Ecology and Environment, Fisheries College, Guangdong Ocean University, Zhanjiang 524088, China; State Key Laboratory of Biocontrol, Institute of Aquatic Economic Animals and the Guangdong Province Key Laboratory for Aquatic Economic Animals, Sun Yat-Sen University, Guangzhou 510275, China.
authors.forename: Shuisheng
authors.initials: S
authors.lastname: Li
authors.affiliation: State Key Laboratory of Biocontrol, Institute of Aquatic Economic Animals and the Guangdong Province Key Laboratory for Aquatic Economic Animals, Sun Yat-Sen University, Guangzhou 510275, China.
authors.forename: Qiongyu
authors.initials: Q
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Biocontrol, Institute of Aquatic Economic Animals and the Guangdong Province Key Laboratory for Aquatic Economic Animals, Sun Yat-Sen University, Guangzhou 510275, China.
authors.forename: Ling
authors.initials: L
authors.lastname: Xiao
authors.affiliation: Zhanjiang City State Key Laboratory of Marine Ecology and Environment, Fisheries College, Guangdong Ocean University, Zhanjiang 524088, China. Electronic address: chpsysu@hotmail.com.
authors.forename: Huapu
authors.initials: H
authors.lastname: Chen
authors.affiliation: State Key Laboratory of Biocontrol, Institute of Aquatic Economic Animals and the Guangdong Province Key Laboratory for Aquatic Economic Animals, Sun Yat-Sen University, Guangzhou 510275, China.
authors.forename: Guangli
authors.initials: G
authors.lastname: Li
authors.affiliation: State Key Laboratory of Biocontrol, Institute of Aquatic Economic Animals and the Guangdong Province Key Laboratory for Aquatic Economic Animals, Sun Yat-Sen University, Guangzhou 510275, China.
authors.forename: Yong
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Biocontrol, Institute of Aquatic Economic Animals and the Guangdong Province Key Laboratory for Aquatic Economic Animals, Sun Yat-Sen University, Guangzhou 510275, China.
authors.forename: Haoran
authors.initials: H
authors.lastname: Lin
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D001492:Bass / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism* / Q000502:physiology; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics; D005260:Female; D029941:Fish Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D005786:Gene Expression Regulation / Q000187:drug effects; D023281:Genomics; D007987:Gonadotropin-Releasing Hormone / Q000235:genetics; D009490:Neurosecretory Systems / Q000187:drug effects / Q000378:metabolism / Q000502:physiology; D010053:Ovary / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism; D036361:Peptide Hormones / Q000494:pharmacology; D010907:Pituitary Hormones / Q000235:genetics
chemical_list: D018076:DNA, Complementary; D029941:Fish Proteins; D036361:Peptide Hormones; D010907:Pituitary Hormones; D007987:Gonadotropin-Releasing Hormone
keywords: Feeding control; Orange-spotted grouper; Reproduction; Spexin