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Evolution of the ovine MHC DQA region
Author(s) -
J G H Hickford,
H J Ridgway,
A P Escayg
Publication year - 2000
Publication title -
animal genetics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.756
H-Index - 81
eISSN - 1365-2052
pISSN - 0268-9146
DOI - 10.1046/j.1365-2052.2000.00635.x
Subject(s) - biology , haplotype , gene duplication , taqi , locus (genetics) , genetics , null allele , allele , gene , restriction fragment length polymorphism , microbiology and biotechnology , polymerase chain reaction
Summary Southern hybridisation was used to define an apparent gene duplication event at the ovine DQA2 locus. Approximately 500 sheep from five different breeds were genotyped at their DQA1 and DQA2 loci. A subset of these were selected for further characterisation. Southern hybridisation of Taq I digested DNA revealed no DQA1 region in some sheep. It was also noted in these DQA1 null animals the DQA2 specific probe hybridised to two bands. An Eco RV‐RFLP designed to distinguish copy number confirmed this duplication of the DQA2 region. The results showed that the duplication was exclusively associated with the DQA1 null haplotype and occured only in alleles DQA2‐F, ‐G, ‐I and ‐J . Comparison with bovine MHC genes revealed that they also contained a DQA1 null haplotype and that this haplotype was associated with a putative DQA3 gene. The potential for an ovine DQA3 locus is discussed.