title: Identification and characterization of Fugu orthologues of mammalian interleukin-12 subunits.
abstract: We have isolated and characterized cDNAs and genes for pufferfish, Fugu rubripes, (Fugu) orthologues of mammalian interleukin (IL)-12 subunits (IL-12 p35 and IL-12 p40). The deduced amino acid sequences of the Fugu IL-12 subunits showed homology with mammalian IL-12 subunits (p35: 50.4-58.0% similarity; p40: 51.2-55.4% similarity). Phylogenetic analysis confirmed that Fugu IL-12 p35 and p40 genes cluster with their mammalian counterpart lineages. The genomic organization of each of the Fugu IL-12 subunit genes is similar to that of the corresponding mouse IL-12 subunit genes, although the Fugu genes are very compact due to small intron size. Comparative genomic analysis showed conserved syntenies within the IL-12 p35 and p40 regions between Fugu and human, indicating that the Fugu IL-12 p35 and p40 genes are orthologues for mammalian IL-12 p35 and p40 encoding genes, respectively. Expression of IL-12 p35 mRNA was observed in lymphoid tissues and several non-lymphoid tissues, while expression of IL-12 p40 mRNA was constitutive and nearly ubiquitous. In the spleen and head kidney, expression of IL-12 p35 was induced by polyriboinosinic polyribocytidylic acid [poly(I:C)] and not by lipopolysaccharide (LPS), while expression of IL-12 p40 was constitutive and unresponsive to both poly(I:C) and LPS. These results indicate that IL-12 levels are regulated by production of IL-12 p35 mRNA and suggest that IL-12 in fish may be involved in antiviral defense. This is the first report of the identification and characterization of IL-12 subunit cDNAs and genes in a non-mammalian vertebrate.
authors.affiliation: Immunology Section, National Research Institute of Aquaculture, Fisheries Research Agency, Tamaki, 519-0423 Mie, Japan. yoshiura@fra.affrc.go.jp
authors.forename: Yasutoshi
authors.initials: Y
authors.lastname: Yoshiura
authors.forename: Ikunari
authors.initials: I
authors.lastname: Kiryu
authors.forename: Atsushi
authors.initials: A
authors.lastname: Fujiwara
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Suetake
authors.forename: Yuzuru
authors.initials: Y
authors.lastname: Suzuki
authors.forename: Teruyuki
authors.initials: T
authors.lastname: Nakanishi
authors.forename: Mitsuru
authors.initials: M
authors.lastname: Ototake
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002417:Cattle; D002874:Chromosome Mapping; D018076:DNA, Complementary; D006801:Humans; D018664:Interleukin-12 / Q000235:genetics*; D053765:Interleukin-12 Subunit p35; D053762:Interleukin-12 Subunit p40; D051379:Mice; D008969:Molecular Sequence Data; D009928:Organ Specificity; D010802:Phylogeny; D021122:Protein Subunits / Q000235:genetics*; D017422:Sequence Analysis, DNA; D023741:Takifugu / Q000235:genetics* / Q000276:immunology
chemical_list: D018076:DNA, Complementary; C508858:IL12A protein, human; D053765:Interleukin-12 Subunit p35; D053762:Interleukin-12 Subunit p40; D021122:Protein Subunits; D018664:Interleukin-12