RESUMO
Several studies have focused on polymorphisms of major histocompatibility complex [MHC] in sheep, Ovar-MHC. This molecule plays a pivotal role in antigen presentation for eliciting immune responses against invading pathogens. The best-characterized genetic control of disease resistance and immune response in animals is associated with MHC. Numerous molecular genetic investigations have been undertaken to detect polymorphisms of MHC genes and their association with resistance to infectious diseases. We have examined Ovar-DRB1 in DNA samples of 82 Shaul Sheep using polymerase chain reaction [PCR] and restriction fragment length polymorphism [RFLP] method. Identities of 8 different patterns and 5 distinct DRB1 alleles among Iranian Shaul Sheep have been determined. PCR-RFLP analysis allows rapid identification of Ovar-DRB1 types and enables rapid discrimination between homozygotes and heterozygotes. Data obtained from the present study have revealed that the exon 2 region of Ovar-DRB1 was highly polymorphic in sheep. So PCR-RFLP can be applied to the analysis of this locus