title: Expression of nitric oxide synthase (NOS) genes in channel catfish is highly regulated and time dependent after bacterial challenges.
abstract: Nitric oxide is well known for its roles in immune responses. As such, its synthesizing enzymes have been extensively studied from various species including some teleost fish species. However, the NOS genes have not been characterized in channel catfish (Ictalurus punctatus). In this study, we identified and characterized three NOS genes including one NOS1 and two NOS2 genes in channel catfish. Comparing with the NOS genes from other fish species, the catfish NOS genes are highly conserved in their structural features. Phylogenetic and syntenic analyses allowed determination of NOS1 and NOS2 genes of channel catfish and their orthology relationships. Syntenic analysis, as well as the phylogenetic analysis, indicated that the two NOS2 genes of catfish were lineage-specific duplication. The NOS genes were broadly expressed in most tested tissues, with NOS1 being expressed at the highest levels in the brain, NOS2b1 highly expressed in the skin and gill, and NOS2b2 lowly expressed in most of the tested tissues. The most striking findings of this study was that the expression of the NOS genes are highly regulated after bacterial infection, with time-dependent expression patterns that parallel the migration of macrophages. After Edwardsiella ictaluri challenge, dramatically different responses among the three NOS genes were observed. NOS1 was only significantly in the skin early after infection, while NOS2b1 was rapidly upregulated in gill, but more up-regulated in trunk kidney with the progression of the disease, suggesting such differences in gene expression may be reflective of the migration of macrophages among various tissues of the infected fish. In contrast to NOS1 and NOS2b1, NOS2b2 was normally expressed at very low levels, but it is induced in the brain and liver while significantly down-regulated in most other tissues.
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.
authors.forename: Chao
authors.initials: C
authors.lastname: Li
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: 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: Jianbin
authors.initials: J
authors.lastname: Feng
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: Ruijia
authors.initials: R
authors.lastname: Wang
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: Yun
authors.initials: Y
authors.lastname: Li
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: Chen
authors.initials: C
authors.lastname: Jiang
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: Lin
authors.initials: L
authors.lastname: Song
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: Ailu
authors.initials: A
authors.lastname: Chen
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; D017124:Conserved Sequence; D020610:Edwardsiella ictaluri / Q000276:immunology; D004756:Enterobacteriaceae Infections / Q000201:enzymology / Q000276:immunology / Q000662:veterinary*; D004790:Enzyme Induction / Q000276:immunology; D005393:Fish Diseases / Q000201:enzymology* / Q000382:microbiology; D029941:Fish Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D045826:Flavobacteriaceae Infections / Q000201:enzymology / Q000276:immunology / Q000662:veterinary*; D005417:Flavobacterium / Q000276:immunology; D015870:Gene Expression / Q000276:immunology; D007059:Ictaluridae / Q000235:genetics* / Q000276:immunology / Q000382:microbiology; D007113:Immunity, Innate; D008969:Molecular Sequence Data; D019001:Nitric Oxide Synthase / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D009928:Organ Specificity; D010802:Phylogeny; D026801:Synteny
chemical_list: D029941:Fish Proteins; D019001:Nitric Oxide Synthase
keywords: Disease; Fish; Genome; Immune response; NOS; Nitric oxide synthase