Genetic polymorphism of the swine major histocompatibility complex ( SLA) class I genes, SLA-1, -2 and -3.
In order to identify and characterize genetic polymorphism of the swine major histocompatibility complex ( Mhc: SLA) class I genes, RT-PCR products of the second and third exons of the three SLA classical class I genes, SLA-1, SLA-2 and SLA-3 were subjected to nucleotide determination. These analyses allowed the identification of four, eight and seven alleles at the SLA-1, SLA-2 and SLA-3 loci, respectively, from three different breeds of miniature swine and one mixed breed. Among them, 12 alleles were novel. Construction of a phylogenetic tree using the nucleotide sequences of those 19 alleles indicated that the SLA-1 and -2 genes are more closely related to each other than to SLA-3. Selective forces operating at single amino acid sites of the SLA class I molecules were analyzed by the Adaptsite Package program. Ten positive selection sites were found at the putative antigen recognition sites (ARSs). Among the 14 positively selected sites observed in the human MHC ( HLA) classical class I molecules, eight corresponding positions in the SLA class I molecules were inferred as positively selected. On the other hand, four amino acids at the putative ARSs were identified as negatively selected in the SLA class I molecules. These results suggest that selective forces operating in the SLA class I molecules are almost similar to those of the HLA class I molecules, although several functional sites for antigen and cytotoxic T-lymphocyte recognition by the SLA class I molecules may be different from those of the HLA class I molecules.
Ando
Asako
A
Department of Molecular Life Science, Tokai University School of Medicine, Bohseidai, Isehara, 259-1193 Kanagawa, Japan.
Kawata
Hisako
H
Shigenari
Atsuko
A
Anzai
Tatsuya
T
Ota
Masao
M
Katsuyama
Yoshihiko
Y
Sada
Masaharu
M
Goto
Rieko
R
Takeshima
Shin-Nosuke
SN
Aida
Yoko
Y
Iwanaga
Takahiro
T
Fujimura
Nobuyuki
N
Suzuki
Yoshiyuki
Y
Gojobori
Takashi
T
Inoko
Hidetoshi
H
D000483:Alleles; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular; D017124:Conserved Sequence; D017931:DNA Primers / Q000737:chemistry; D018076:DNA, Complementary / Q000235:genetics; D005091:Exons / Q000235:genetics; D005805:Genes, MHC Class I / Q000235:genetics*; D005838:Genotype; D006801:Humans; D008969:Molecular Sequence Data; D010802:Phylogeny; D011110:Polymorphism, Genetic / Q000235:genetics*; D012313:RNA / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017386:Sequence Homology, Amino Acid; D012689:Sequence Homology, Nucleic Acid; D013552:Swine / Q000235:genetics*
D017931:DNA Primers; D018076:DNA, Complementary; D012313:RNA