title: Identification, phylogeny and expression analysis of suppressors of cytokine signaling in channel catfish.
abstract: The suppressors of cytokine signaling (SOCS) family genes play important roles in regulating a variety of signal transduction pathways that are involved in immunity, growth and development. Because of their importance, they have been extensively studied in mammalian species, but they have not been systematically studied among teleost fish species. In this study, a total of 12 SOCS genes were characterized to understand the molecular mechanisms of SOCS function in channel catfish. Phylogenetic analyses suggested that all SOCS were clustered into two main clusters. Further syntenic analysis confirmed the phylogenetic analyses and allowed the annotation of SOCS genes in channel catfish. This work, for the first time, determined the expression profiles of the 12 SOCS genes after bacterial infections with Flavobacterium columnare and Edwardsiella ictaluri in channel catfish. The SOCS1a and SOCS3a were significantly up-regulated at 4h after F. columnare challenge in the gill, but were down-regulated at later stages of pathogenesis. Similarly, SOCS1a and CISH were significantly up-regulated at 3h in intestine under E. ictaluri infection, but were down-regulated at later stages of pathogenesis at 24h and 3 days after infection. These expression patterns may indicate that SOCS genes could be induced in acute immune responses after bacterial infections, but the massive cytokine expression, especially chemokine expression after the first day of infection may have had negative feedback leading to the overall down-regulation of the expression of SOCS genes. Moreover, the differential expression patterns of SOCS genes in the catfish gill and intestine after F. columnare and E. ictaluri infection demonstrated that the regulation of SOCS gene expression was both tissue-specific and time-dependent. Taken together, these results suggested that SOCS genes were involved in immune responses to bacterial invasions, and these results set the foundation for future studies of SOCS gene functions.
authors.affiliation: The Fish Molecular Genetics and Biotechnology Laboratory, Aquatic Genomics Unit, School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL 36849, USA.
authors.forename: Jun
authors.initials: J
authors.lastname: Yao
authors.affiliation: The Fish Molecular Genetics and Biotechnology Laboratory, Aquatic Genomics Unit, School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL 36849, USA; Fisheries College, Ocean University of China, 5 Yushan Road, Qingdao 266003, Shandong, PR China.
authors.forename: Weijie
authors.initials: W
authors.lastname: Mu
authors.affiliation: The Fish Molecular Genetics and Biotechnology Laboratory, Aquatic Genomics Unit, School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL 36849, USA.
authors.forename: Shikai
authors.initials: S
authors.lastname: Liu
authors.affiliation: The Fish Molecular Genetics and Biotechnology Laboratory, Aquatic Genomics Unit, School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL 36849, USA.
authors.forename: Jiaren
authors.initials: J
authors.lastname: Zhang
authors.affiliation: Fisheries College, Ocean University of China, 5 Yushan Road, Qingdao 266003, Shandong, PR China.
authors.forename: Haishen
authors.initials: H
authors.lastname: Wen
authors.affiliation: The Fish Molecular Genetics and Biotechnology Laboratory, Aquatic Genomics Unit, School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL 36849, USA. Electronic address: liuzhan@auburn.edu.
authors.forename: Zhanjiang
authors.initials: Z
authors.lastname: Liu
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D016207:Cytokines / Q000096:biosynthesis / Q000276:immunology; D020610:Edwardsiella ictaluri / Q000276:immunology; D005393:Fish Diseases / Q000235:genetics / Q000276:immunology* / Q000382:microbiology; D029941:Fish Proteins / Q000145:classification / Q000235:genetics / Q000276:immunology* / Q000302:isolation & purification; D005417:Flavobacterium / Q000276:immunology; D005786:Gene Expression Regulation; D005880:Gills / Q000276:immunology* / Q000382:microbiology; D007059:Ictaluridae / Q000235:genetics / Q000276:immunology* / Q000382:microbiology; D007113:Immunity, Innate; D007422:Intestines / Q000276:immunology* / Q000382:microbiology; D008969:Molecular Sequence Data; D009928:Organ Specificity; D010802:Phylogeny; D016415:Sequence Alignment; D015398:Signal Transduction; D050826:Suppressor of Cytokine Signaling Proteins / Q000145:classification / Q000235:genetics / Q000276:immunology* / Q000302:isolation & purification; D013997:Time Factors
chemical_list: D016207:Cytokines; D029941:Fish Proteins; D050826:Suppressor of Cytokine Signaling Proteins
keywords: Expression; Fish; Gene; Genome; Phylogeny; SOCS