title: Cloning and sequence analysis of cDNAs encoding the MHC class II beta chain in Atlantic salmon (Salmo salar).
abstract: Atlantic salmon (Salmo salar) cDNAs encoding the major histocompatibility complex (Mhc-Sasa) class II beta chain were isolated from a leucocyte library by a polymerase chain reaction (PCR) approach. Three different cDNAs (c144, c22, and c157) encoding the entire mature beta chain have been analyzed. Clone c144 differs from clone c157 in 12.6% of the nucleotides in the beta 1-encoding region. The corresponding differences between clones c144 and c22, and clones c22 and c157, are 10.3% and 5.2%, respectively. This variation is, at least in part, most likely attributable to allelism. The similarity indices between the highly conserved beta 2 domains from Atlantic salmon and corresponding sequences from humans (DQ beta), chicken (BL beta), carp (TLAII beta-1), and rainbow trout (O.M. No. 55) are 45%, 40%, 66%, and 97%, respectively. Variable residues in the beta 1 domains from Atlantic salmon correspond with polymorphic sites of beta 1 domains from higher vertebrates. The frequency of substitutions in the beta 1-encoding region exceeds that in the 3'-untranslated (UT) region with several folds, indicating extensive beta 1 polymorphism in Atlantic salmon.
authors.affiliation: Center of Biotechnology, University of Bergen, Norway.
authors.forename: I
authors.initials: I
authors.lastname: Hordvik
authors.forename: U
authors.initials: U
authors.lastname: Grimholt
authors.forename: V M
authors.initials: VM
authors.lastname: Fosse
authors.forename: O
authors.initials: O
authors.lastname: Lie
authors.forename: C
authors.initials: C
authors.lastname: Endresen
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular; D004247:DNA / Q000235:genetics; D005802:Genes, MHC Class II; D000949:Histocompatibility Antigens Class II / Q000235:genetics*; D008969:Molecular Sequence Data; D011110:Polymorphism, Genetic; D012474:Salmon / Q000235:genetics*; D016415:Sequence Alignment
chemical_list: D000949:Histocompatibility Antigens Class II; D004247:DNA