title: Molecular cloning, characterization and functional analysis of QRFP in orange-spotted grouper (Epinephelus coioides).
abstract: The peptide QRFP plays an important role in the regulation of vertebrate feeding behavior. In this study, we cloned the full length cDNA of a QRFP precursor in a teleost fish, the orange-spotted grouper (Epinephelus coioides). Sequence analysis has shown that the functional regions of QRFP in other vertebrates (QRFP-25 and QRFP-7) are conserved in orange-spotted grouper. RT-PCR demonstrated that the pre-processed mRNA of QRFP is widely expressed in orange-spotted grouper. Three days of food deprivation did not change the hypothalamic pre-processed QRFP expression. However, QRFP expression significantly increased when the fish were reefed after three days of fasting. Intraperitoneal injection of QRFP-25 peptide to orange-spotted grouper suppressed expression of orexin, but elevated expression of pro-opiomelanocortin (POMC) in the hypothalamus. We also investigated the effects of QRFP-25 on the expression of reproductive genes. The peptide suppressed the expression of seabream-type gonadotropin-releasing hormones (sbGnRH), luteinizing hormone beta subunit (LHβ) and follicle-stimulating hormone beta subunit (FSHβ) in vivo, as well as inhibited the expression of LHβ and FSHβ in pituitary cells in primary culture. Our results indicate that QRFP may play an inhibitory role in the regulation of feeding behavior and reproduction in orange-spotted grouper.
authors.affiliation: School of Life Sciences, Guangzhou University, Guangzhou 510006, China. Electronic address: shuhu001@126.com.
authors.forename: Hu
authors.initials: H
authors.lastname: Shu
authors.affiliation: Fisheries College, Guangdong Ocean University, Zhanjiang 524088, China; Zebrafish Platform, Affiliated Hospital of Guangdong Medical College, Guangdong Medical College, Zhanjiang 524001, China. Electronic address: chpsysu@hotmail.com.
authors.forename: Huapu
authors.initials: H
authors.lastname: Chen
authors.affiliation: School of Biomedical Sciences, The Chinese University of Hong Kong, Hong Kong, China.
authors.forename: Yun
authors.initials: Y
authors.lastname: Liu
authors.affiliation: School of Life Sciences, Guangzhou University, Guangzhou 510006, China.
authors.forename: Lidong
authors.initials: L
authors.lastname: Yang
authors.affiliation: Guangdong Daya Bay Fisheries Development Center, Huizhou 516081, China.
authors.forename: Yuqing
authors.initials: Y
authors.lastname: Yang
authors.affiliation: Guangdong Daya Bay Fisheries Development Center, Huizhou 516081, China.
authors.forename: Haifa
authors.initials: H
authors.lastname: Zhang
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D001492:Bass / Q000378:metabolism*; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics; D004435:Eating / Q000502:physiology; D005508:Food Deprivation; D007031:Hypothalamus / Q000378:metabolism; D036341:Intercellular Signaling Peptides and Proteins; D008969:Molecular Sequence Data; D009928:Organ Specificity; D036361:Peptide Hormones / Q000378:metabolism; D010455:Peptides / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D061251:Primary Cell Culture; D012098:Reproduction / Q000502:physiology; D017422:Sequence Analysis, DNA
chemical_list: D018076:DNA, Complementary; D036341:Intercellular Signaling Peptides and Proteins; D036361:Peptide Hormones; D010455:Peptides; C511787:QRFP peptide
keywords: Feeding; Orange-spotted grouper; QRFP; Reproduction