title: Cloning and expression analysis of interferon regulatory factor 7 in the Pacific cod, Gadus macrocephalus.
abstract: Interferon regulatory factor 7 (IRF7) plays an important role in regulating the response of type I interferon (IFN) to viral infection. To understand the mechanisms underlying immune reactions in the Pacific cod, Gadus macrocephalus, the gene encoding G. macrocephalus IRF7 was cloned and characterized. The cDNA of G. macrocephalus IRF7 was also cloned and sequenced. A cDNA sequence of 2032 bp was assembled using polymerase chain reaction (PCR) products. It contains an open reading frame of 1323 bp in length, which encoded a 440-amino acid polypeptide that comprised a DNA-binding domain (DBD), an IRF association domain (IAD), and a serine-rich domain (SRD). In the DBD, the tryptophan cluster consisted of only four tryptophans, which is a unique characteristic in fish IRF7. The mRNA of IRF7 was detected in various tissues, including in the spleen, thymus, kidney, intestine, and gills, using relative quantification PCR (R-qPCR). Dynamic expression of IRF7 was observed in larvae throughout post-hatching (ph) development, with the highest level detected at day of ph (dph) 25. Response to immune stimulation was examined by challenging larvae with polyriboinosinic polyribocytidylic acid (pIC) to mimic viral infection and elicit an immune reaction. R-qPCR revealed that the expression of IRF7 significantly increased in pIC-treated groups relative to that in the control groups, in a time-dependent manner, with peak responses at 48 and 72 h after pIC-treatment. These results show that IRF7 is expressed in various tissues of adult fish and larvae and is sensitive to viral infection, suggesting that it plays a role in antiviral immune defense in G. macrocephalus.
authors.affiliation: Key Laboratory of Mariculture & Stock Enhancement in North China's Sea, Ministry of Agriculture, Dalian Ocean University, Dalian 116023, China.
authors.forename: Hang
authors.initials: H
authors.lastname: Sun
authors.affiliation: Key Laboratory of Mariculture & Stock Enhancement in North China's Sea, Ministry of Agriculture, Dalian Ocean University, Dalian 116023, China. Electronic address: zhqjiang@dlou.edu.cn.
authors.forename: Zhiqiang
authors.initials: Z
authors.lastname: Jiang
authors.affiliation: Key Laboratory of Mariculture & Stock Enhancement in North China's Sea, Ministry of Agriculture, Dalian Ocean University, Dalian 116023, China.
authors.forename: Mingguang
authors.initials: M
authors.lastname: Mao
authors.affiliation: Key Laboratory of Mariculture & Stock Enhancement in North China's Sea, Ministry of Agriculture, Dalian Ocean University, Dalian 116023, China.
authors.forename: Yuan
authors.initials: Y
authors.lastname: Huo
authors.affiliation: Key Laboratory of Mariculture & Stock Enhancement in North China's Sea, Ministry of Agriculture, Dalian Ocean University, Dalian 116023, China.
authors.forename: Yuzhe
authors.initials: Y
authors.lastname: Han
authors.affiliation: Key Laboratory of Mariculture & Stock Enhancement in North China's Sea, Ministry of Agriculture, Dalian Ocean University, Dalian 116023, China.
authors.forename: Saisai
authors.initials: S
authors.lastname: Zhang
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics / Q000378:metabolism; D029941:Fish Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D048388:Gadiformes / Q000235:genetics* / Q000276:immunology / Q000378:metabolism; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation / Q000187:drug effects; D007113:Immunity, Innate; D007369:Interferon Inducers / Q000494:pharmacology; D050839:Interferon Regulatory Factor-7 / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D010802:Phylogeny; D011070:Poly I-C / Q000494:pharmacology; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D016415:Sequence Alignment / Q000662:veterinary
chemical_list: D018076:DNA, Complementary; D029941:Fish Proteins; D007369:Interferon Inducers; D050839:Interferon Regulatory Factor-7; D012333:RNA, Messenger; D011070:Poly I-C
keywords: Gadus macrocephalus; Gene expression; Innate immune response; Interferon regulatory factor7; Larvae