title: Cloning and expression analysis of Atlantic halibut (Hippoglossus hippoglossus) CD3 genes.
abstract: The CD3 complex is in higher vertebrates shown to be important for the activation of T-cells. The T-cell system in fish is believed to be similar to that in higher vertebrates, and the CD3 chains could therefore be an important marker for identification of T-cells in fish. Here, we report the cDNA and corresponding gene sequence of Atlantic halibut (Hippoglossus hippoglossus) CD3gammadelta, CD3varepsilon, and CD3zeta chains, and the tissue-specific expression pattern of CD3 and T- cell receptor (TCR) genes. Important structural characteristics defining the CD3 genes seemed to be conserved in the halibut CD3 chains, such as a signal peptide, an extracellular region, a transmembrane helix having a negatively charged residue, and an ITAM bearing cytoplasmic tail. The extracellular domain of halibut CD3gammadelta and CD3varepsilon included two cysteines presumably involved in Ig-fold stabilisation and the CxxCxE motif important for dimerization. A spliced variant of CD3varepsilon was identified, lacking the Ig-fold, but with the CxxCxE motif intact. The real time RT-PCR analysis revealed a highly similar expression pattern of the CD3 genes and the TCRalpha and TCRbeta genes, indicating that the functional relationship between the TCR and the CD3 genes are preserved in teleosts.
authors.affiliation: Institute of Marine Research, P.O. Box 1870 Nordnes, N-5817 Bergen, Norway. basantadas@yahoo.com
authors.forename: Aina-Cathrine
authors.initials: AC
authors.lastname: Overgård
authors.forename: Ivar
authors.initials: I
authors.lastname: Hordvik
authors.forename: Audun Helge
authors.initials: AH
authors.lastname: Nerland
authors.forename: Gisle
authors.initials: G
authors.lastname: Eikeland
authors.forename: Sonal
authors.initials: S
authors.lastname: Patel
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D017252:CD3 Complex / Q000096:biosynthesis / Q000235:genetics* / Q000276:immunology; D003001:Cloning, Molecular; D005432:Flounder / Q000235:genetics / Q000276:immunology*; D008969:Molecular Sequence Data; D010802:Phylogeny; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D019105:Random Amplified Polymorphic DNA Technique / Q000662:veterinary; D011948:Receptors, Antigen, T-Cell / Q000096:biosynthesis / Q000235:genetics* / Q000276:immunology; D016415:Sequence Alignment
chemical_list: D017252:CD3 Complex; D012333:RNA, Messenger; D011948:Receptors, Antigen, T-Cell