Objective:To clone swine leukocyte antigen,class II,DO alpha (SLA-DOA) gene from Banna mini-pig inbred line (BMI) and detect its mRNA expression level in 19 important tissues.Methods:The complete eDNA sequence of SLA-DOA gene was cloned by RT-PCR method from BMI and the mRNA expression pattern in BMI important tissues was examined by semi-quantative RT-PCR method.Nucleotide and protein sequences of SIA-DOA were used to carry out bioinformatics analysis and construct the phylogenetic tree.Results:The eDNA length of BMI SLA-DOA was 1 079 bp,which encoded a protein of 250 amino acids with molecular weight (Mw) 27.81 kD,and isoelectric point (pI) 6.48.Genome structure analysis showed it localized to Sus scrofa chromosomes 7 and consisted of four exons and three introns.Semi-quantitative expression analysis showed that SLA-DOA gene expressed highly in the lymph nodes and stomach;weakly in the heart,skin and duodenum and none in other 14 tissues.Functional bioinformatics analysis indicated that SLA-DOA protein contained one signal poptide,one transmembrane region,three conserved domains,four O-GlcNAc glycosylation sites,18 potential phosphorylation sites and to be located in the cytoplasm with 94.1％ certainty.Phylogenetic analysis demonstrated that BMI (pig) had the closest relationship with cattle.Conclusion:This study have successfully cloned the SLA-DOA gene of Banna mini-pig inbred line,performed bioinformatics analysis and tissue expression profile analysis.It will provide a basis for the studies of BMI xenotransplantation.