Characterization of swine leukocyte antigen polymorphism by sequence-based and PCR-SSP methods in Meishan pigs

Resource herds of swine leukocyte antigen (SLA)-characterized pigs are an important tool for the study of immune responses, disease resistance, and production traits. They are also valuable large animal models for biomedical research, such as transplantation. The Meishan breed of pig is an economically significant breed that is available at several research institutions in the United States. We have characterized the SLA polymorphism of the breeding stock in the herd maintained at the University of Illinois and developed a simple assay to SLA type individuals within that herd. We have used a reverse transcription-polymerase chain reaction (RT-PCR)-based SLA typing method to clone and DNA sequence 19 SLA alleles at three SLA class Ia (SLA-1, SLA-2, and SLA-3) and two SLA class II (SLA-DRB1 and SLA-DQB1) loci. Based on this sequence information, a rapid SLA typing assay was developed to discriminate each allele using PCR with sequence-specific primers (PCR-SSP). Using this method, we were able to characterize the entire Meishan breeding stock and identify four SLA haplotypes present in the herd. The combination of SLA typing by cloning and DNA sequencing with PCR-SSP is therefore a valuable tool for the characterization of SLA alleles and haplotypes in resource herds of pigs.