RESUMO
In order to clone class II DRA and DRB genes of swine leukocyte antigen (SLA) in Hunan Shaziling pigs, to analyze their characteristics and polymorphism and to provide immunological basic parameters for xenotransplantation from pigs to humans. SLA-DRA and SLA-DRB genes in two Shaziling pigs with the absence of porcine endogenous retrovirus (PERV) env-c were amplified by RT-PCR, cloned into PUCm-T vectors, sequenced and analyzed through BLAST in NCBI and related software in ExPASY. The obtained SLA-DRA and SLA-DRB genes of Shaziling pigs were 1,177 and 909 nucleotides in length with their accession numbers in Genbank as EF143987 and EF143988. Bioinformatics analyses have shown that they both contain opening reading frame (ORF) and encode 252 and 266 amino acids respectively. Comparing the ORF and protein sequences of the Shaziling SLA-DRA and SLA-DRB genes with their counterpart sequences of human, the homologies of nucleotide sequences were 83% and 83%, and the homologies of amino acid sequences 83 % and 79% respectively. Further comparison with SLA sequences published in GenBank indicated that SLA-DRB gene found in Shaziling pigs has polymorphism while the homology of SLA-DRA gene is up to 100 % .