title: UII and UT in grouper: cloning and effects on the transcription of hormones related to growth control.
abstract: Urotensin II (UII) is a cyclic peptide that was originally extracted from the caudal neurosecretory system (CNSS) of fish. UII is well known to exhibit cardiovascular, ventilatory, and motor effects in vertebrates. Studies have reported that UII exerts mitogenic effects and can act as an autocrine/paracrine growth factor in mammals. However, similar information in fish is limited. In this study, the full-length cDNAs of UII and its receptor (UT) were cloned and characterized in the orange-spotted grouper. UII and UT were expressed ubiquitously in various tissues in grouper, and particularly high levels were observed in the CNSS, CNS, and ovary. A functional study showed that UT was coupled with intracellular Ca2+ mobilization in HEK293 cells. Studies carried out using i.p. injections of UII in grouper showed the following: i) in the hypothalamus, UII can significantly stimulate the mRNA expression of ghrh and simultaneously inhibit the mRNA expression of somatostatin 1 (ss1) and ss2 3 h after injection; ii) in the pituitary, UII also significantly induced the mRNA expression of gh 6 and 12  h after injection; and iii) in the liver, the mRNA expression levels of ghr1/ghr2 and igf1/igf2 were markedly increased 12 and 3  h after the i.p. injection of UII respectively. These results collectively indicate that the UII/UT system may play a role in the promotion of the growth of the orange-spotted grouper.
authors.affiliation: State Key Laboratory of Biocontrol, Institute of Aquatic Economic Animals and Guangdong Provincial Key Laboratory for Aquatic Economic Animals, School of Life Sciences, Sun Yat-Sen University, No. 135, XinGang West Road, Guangzhou 510275, People's Republic of China.
authors.forename: Caiyun
authors.initials: C
authors.lastname: Sun
authors.forename: Da
authors.initials: D
authors.lastname: Duan
authors.forename: Bo
authors.initials: B
authors.lastname: Li
authors.forename: Chaobin
authors.initials: C
authors.lastname: Qin
authors.forename: Jirong
authors.initials: J
authors.lastname: Jia
authors.forename: Bin
authors.initials: B
authors.lastname: Wang
authors.forename: Haiyan
authors.initials: H
authors.lastname: Dong
authors.forename: Wensheng
authors.initials: W
authors.lastname: Li
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002118:Calcium / Q000378:metabolism; D002490:Central Nervous System / Q000378:metabolism; D003001:Cloning, Molecular; D005260:Female; D029941:Fish Proteins / Q000235:genetics*; D005399:Fishes / Q000235:genetics*; D015870:Gene Expression / Q000187:drug effects; D020869:Gene Expression Profiling; D013006:Growth Hormone / Q000235:genetics; D057809:HEK293 Cells; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000235:genetics; D007335:Insulin-Like Growth Factor II / Q000235:genetics; D042541:Intracellular Space / Q000378:metabolism; D008969:Molecular Sequence Data; D009490:Neurosecretory Systems / Q000378:metabolism; D010053:Ovary / Q000378:metabolism; D043562:Receptors, G-Protein-Coupled / Q000235:genetics*; D011986:Receptors, Somatotropin / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017386:Sequence Homology, Amino Acid; D013004:Somatostatin / Q000235:genetics; D014579:Urotensins / Q000235:genetics* / Q000494:pharmacology
chemical_list: D029941:Fish Proteins; D043562:Receptors, G-Protein-Coupled; D011986:Receptors, Somatotropin; D014579:Urotensins; D013004:Somatostatin; D007334:Insulin-Like Growth Factor I; D007335:Insulin-Like Growth Factor II; D013006:Growth Hormone; C029677:urotensin II; D002118:Calcium
keywords: UT; growth; mRNA expression; orange-spotted grouper; urotensin II