title: A divergent non-classical class I gene conserved in salmonids.
abstract: Complementary DNA for two class I genes of the rainbow trout, Oncorhynchus mykiss, were characterized. MhcOnmy-UBA*01 is similar to Onmy-UAC32 and the classical major histocompatibility complex class I genes of other fish species, whereas Onmy-UAA*01 is divergent from all class I genes so far characterized. Onmy-UAA*01 is expressed at lower levels than Onmy-UBA*01. Although Onmy-UAA*01 exhibits restriction fragment length polymorphism on Southern blotting, the encoded protein is highly conserved. Two allotypes, which differ only by substitution at amino acid position 223 of the alpha 3 domain, have been defined. Onmy-UAA*01 has an exon-intron organization like other class I genes and contains a Tc1-like transposon element in intron III. Orthologues of Onmy-UAA*01 have been characterized in four other species of salmonid. Between four species of Oncorhynchus, UAA*01 proteins differ by only 2-6 amino acids, whereas comparison of Oncorhynchus with Salmo trutta (brown trout) reveals 14-16 amino acid differences. The Onmy-UAA*01 gene has properties indicative of a particularly divergent non-classical class I gene.
authors.affiliation: Department of Structural Biology and Microbiology, Stanford University School of Medicine, CA 94305-5126, USA.
authors.forename: B P
authors.initials: BP
authors.lastname: Shum
authors.forename: R
authors.initials: R
authors.lastname: Rajalingam
authors.forename: K E
authors.initials: KE
authors.lastname: Magor
authors.forename: K
authors.initials: K
authors.lastname: Azumi
authors.forename: W H
authors.initials: WH
authors.lastname: Carr
authors.forename: B
authors.initials: B
authors.lastname: Dixon
authors.forename: R J
authors.initials: RJ
authors.lastname: Stet
authors.forename: M A
authors.initials: MA
authors.lastname: Adkison
authors.forename: R P
authors.initials: RP
authors.lastname: Hedrick
authors.forename: P
authors.initials: P
authors.lastname: Parham
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D004251:DNA Transposable Elements; D018076:DNA, Complementary; D005805:Genes, MHC Class I; D006801:Humans; D007438:Introns; D008969:Molecular Sequence Data; D017686:Oncorhynchus mykiss / Q000235:genetics* / Q000276:immunology; D010802:Phylogeny; D011110:Polymorphism, Genetic; D017386:Sequence Homology, Amino Acid; D012689:Sequence Homology, Nucleic Acid
chemical_list: D004251:DNA Transposable Elements; D018076:DNA, Complementary