A divergent non-classical class I gene conserved in salmonids.
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.
Shum
B P
BP
Department of Structural Biology and Microbiology, Stanford University School of Medicine, CA 94305-5126, USA.
Rajalingam
R
R
Magor
K E
KE
Azumi
K
K
Carr
W H
WH
Dixon
B
B
Stet
R J
RJ
Adkison
M A
MA
Hedrick
R P
RP
Parham
P
P
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
D004251:DNA Transposable Elements; D018076:DNA, Complementary