Identification of genetic variation in the major histocompatibility complex gene region in Turkish sheep breeds
The major histocompatibility complex (MHC) in sheep, Ovar-Mhc, remains poorly characterized relative to other domestic animals. However, its basic structure is similar to that of other mammals, comprising class I, II and III regions. In this study, the Ovine MHC class II DRB1 and DRB3 genes were amplified by polymerase chain reaction in eight sheep breeds reared in Turkey. Informative restriction fragment length polymorphisms (RFLPs) were obtained with five restriction enzymes for DRB1 and with two restriction enzymes for DRB3. The digestion of DRB1 exon 2 with NciI, SacI, SacII, Hin1I each produced three genotypes and two alleles (viz., a and b) with frequencies of 0.69 and 0.31; 0.65 and 0.35; 0.91 and 0.09; 0.57 and 0.43, respectively. The digestion of DRB1 exon 2 with DdeI produced four genotypes and three alleles (viz., a, b and c) with frequencies of 0.62, 0.28 and 0.10, respectively. On the other hand, the digestion of DRB3 exon 2 with NdeII and BsaI each produced three genotypes and two alleles (viz., a and b) with frequencies of 0.72 and 0.28; 0.96 and 0.04, respectively. This study presents the genetic profiles of the exon 2 region of the MHC DRB1 and DRB3 genes in native Turkish sheep breeds.
Keywords: DRB1, DRB3, polymerase chain reaction (PCR), restriction fragment length polymorphism (RFLP)