title: Molecular cloning and expression analysis of interferon stimulated gene 15 (ISG15) in turbot, Scophthalmus maximus.
abstract: The interferon stimulated gene 15 (ISG15) is strongly induced in many cell types by double-stranded RNA (polyinosinic: polycytidylic acid, poly I:C) and viral infection. In this study, we described the nucleotide, mRNA tissue distribution and regulation of an ISG15 gene from turbot, Scophthalmus maximus (SmISG15). SmISG15 gene is 862 bp in length, composed of two exons and one intron, and encodes 158 amino acids. The deduced protein exhibits the highest homology (44.7-71.2% identity) with ISG15s from other fishes and possesses two conserved tandem ubiquitin-like (UBL) domains and a C-terminal RLRGG conjugating motif known to be important for the functions of ISG15s in vertebrates. Phylogenetic analysis grouped SmISG15 into fish ISG15. SmISG15 mRNA was constitutively expressed in all tissues examined, with higher levels observed in immune organs. Gene expression analysis was performed for SmISG15 in the spleen, head kidney, gills and muscle of turbots challenged with poly I:C or turbot reddish body iridovirus (TRBIV) over a 7-day time course. The result showed that SmISG15 was upregulated by both stimuli in all four tissues, with induction by poly I:C apparently stronger and initiated more quickly. A two-wave induced expression of SmISG15 was seen in the spleen, head kidney and gills, suggesting an induction of SmISG15 either by IFN-dependent or -independent pathway. These results provide insights into the roles of fish ISG15 in antiviral immunity.
authors.affiliation: College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China.
authors.forename: Jing-Yun
authors.initials: JY
authors.lastname: Lin
authors.affiliation: College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China; Institute of Evolution & Marine Biodiversity, Ocean University of China, Qingdao 266003, China. Electronic address: huguobin@mail.ouc.edu.cn.
authors.forename: Guo-Bin
authors.initials: GB
authors.lastname: Hu
authors.affiliation: Institute of Evolution & Marine Biodiversity, Ocean University of China, Qingdao 266003, China.
authors.forename: Da-Hai
authors.initials: DH
authors.lastname: Liu
authors.affiliation: College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China.
authors.forename: Song
authors.initials: S
authors.lastname: Li
authors.affiliation: College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China.
authors.forename: Qiu-Ming
authors.initials: QM
authors.lastname: Liu
authors.affiliation: College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China; Institute of Evolution & Marine Biodiversity, Ocean University of China, Qingdao 266003, China.
authors.forename: Shi-Cui
authors.initials: SC
authors.lastname: Zhang
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics / Q000378:metabolism; D029941:Fish Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D005412:Flatfishes / Q000235:genetics* / Q000276:immunology* / Q000378:metabolism; D005786:Gene Expression Regulation; D007113:Immunity, Innate; D007369:Interferon Inducers / Q000008:administration & dosage / Q000494:pharmacology; D007497:Iridoviridae / Q000502:physiology; D008969:Molecular Sequence Data; D011070:Poly I-C / Q000008:administration & dosage / Q000494:pharmacology; D012330:RNA, Double-Stranded / Q000008:administration & dosage / Q000502:physiology; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D016415:Sequence Alignment / Q000662:veterinary
chemical_list: D018076:DNA, Complementary; D029941:Fish Proteins; D007369:Interferon Inducers; D012330:RNA, Double-Stranded; D012333:RNA, Messenger; D011070:Poly I-C
keywords: Gene expression; ISG15; Poly I:C; Scophthalmus maximus; TRBIV