|Morrison, Cheryl - USGS LEETOWN SCIENCE CENT|
Submitted to: International Immunology Congress
Publication Type: Abstract Only
Publication Acceptance Date: April 5, 2004
Publication Date: July 18, 2004
Citation: Wiens, G.D., Gahr, S.A., Morrison, C., Palti, Y., Rexroad III, C.E., Rodriguez, M.F., Welch, T.J. 2004. Genomic characterization and expression analysis of a tumor necrosis factor superfamily 13b (tnfsf 13b) homologue from rainbow trout (oncorhynchus mykiss). International Immunology Congress p. 82C (abstract W15.15). Technical Abstract: RATIONAL: Little is known about molecules that regulate fish B cell function. Such knowledge is important for selecting disease resistant fish and developing successful vaccines. We sought to identify members of the tumor necrosis factor superfamily (TNFSF) because of their important roles in the regulation of mammalian B cell survival and antibody production. METHODS: To identify expressed TNFSF genes, we searched a computer database of ~50,000 rainbow trout expressed sequence tags generated at the National Center for Cool and Cold Water Aquaculture. RESULTS: Here, we report the characterization of a cDNA, 1RT126I22, which contains a TNF homology domain. Phylogenetic analyses group 1RT126I22 with TNFSF 13b which is also known as B-cell activating factor (BAFF) or B-lymphocyte stimulating factor (BLyS). The trout TNFSF 13b predicted protein shares 54% amino acid identity with human and chicken TNFSF 13b, and 51% identity with mouse TNFSF 13b. We identified zebrafish and Fugu TNFSF 13b homologues by genomic DNA database searches and determined that the predicted proteins share 68% and 76% sequence identity with trout TNFSF 13b. An Atlantic salmon gene has been cloned that is identical to trout TNFSF 13b. Three introns were identified in the rainbow trout, Atlantic salmon and zebrafish genomic sequences, and the intron locations correspond closely to those in the mammalian TNFSF 13b genes. Bacterial artificial chromosome clones have been isolated from a trout library to further facilitate genomic characterization. Trout TNFSF 13b RNA is expressed in immune tissues including the spleen, anterior kidney, and peripheral blood leukocytes but not in the liver. The involvement of trout TNFSF 13b in B cell function is under investigation. CONCLUSIONS: To our knowledge, this is the first identification and expression analysis of fish TNFSF 13b. These findings indicate a conservation of TNFSF 13b during vertebrate evolution.