title: Cloning and expression of TNF-alpha, IL-1beta and COX-2 in an anadromous and landlocked strain of Atlantic salmon (Salmo salar L.) during the smolting period.
abstract: The parr-smolt transformation involves complex modulation of immune parameters, affecting both cell populations and humoral factors. The expression of cytokines was studied in salmon cells and tissues during this period using an anadromous and a landlocked freshwater resident dwarf strain of Atlantic salmon (Salmo salar L.). The constitutive activity of three immunoregulatory genes encoding the cytokines tumour necrosis factor-alpha (TNF-alpha) and interleukin-1beta (IL-1beta) and the cyclo-oxygenase (COX) isoform COX-2 was investigated in head kidney, spleen and gill tissue from healthy, unvaccinated fish by real-time PCR. The TNF-alpha gene was generally lower expressed than COX-2 and IL-1beta1, which were approximately expressed at equal levels and constitutive expression was seen for COX-2 and IL-1beta1 in all tissues examined and at all sampling dates. The expression of all three genes in head kidney and spleen tissue seemed to be highest at the sampling in May for both strains around the time of seawater transfer suggesting an influence of smolting related hormones on cytokine expression. The gill tissue experienced the highest expression of IL-1beta1 and COX-2 at all sampling dates indicating that this organ is immunologically important.
authors.affiliation: Department of Biology, University of Bergen, P.O. Box 7800, N-5020 Bergen, Norway.
authors.forename: H C
authors.initials: HC
authors.lastname: Ingerslev
authors.forename: C
authors.initials: C
authors.lastname: Cunningham
authors.forename: H I
authors.initials: HI
authors.lastname: Wergeland
mesh_terms: D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular; D051546:Cyclooxygenase 2 / Q000235:genetics / Q000378:metabolism*; D017931:DNA Primers; D015870:Gene Expression; D005880:Gills / Q000378:metabolism; D007375:Interleukin-1 / Q000235:genetics / Q000378:metabolism*; D007668:Kidney / Q000378:metabolism; D008018:Life Cycle Stages / Q000235:genetics*; D008969:Molecular Sequence Data; D020133:Reverse Transcriptase Polymerase Chain Reaction; D020317:Salmo salar / Q000235:genetics* / Q000378:metabolism; D017422:Sequence Analysis, DNA; D013154:Spleen / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics / Q000378:metabolism*
chemical_list: D017931:DNA Primers; D007375:Interleukin-1; D014409:Tumor Necrosis Factor-alpha; D051546:Cyclooxygenase 2