Genomic hybridization of bovine class II major histocompatibility genes: 2. Polymorphism of DR genes and linkage disequilibrium in the DQ‐DR region

Publisher Website
Google Scholar
Abstract
Class II genes of the bovine major histocompatibility complex have been investigated by Southern blot analysis using human cDNA probes for DQ.alpha., DQ.beta., DR.alpha. and DR.beta.. In this report restriction fragment length polymorphisms of DR.alpha. and DR.beta. are described. The polymorphisms were interpreted genetically by analysing five paternal half-sib families of the Swedish Red and White Breed, comprising altogether 28 offspring. Using the restriction enzymes BamHI, EcoRI and PvuII, three DR.alpha. and three DR.beta. allelic fragment patterns were resolved. The DR.alpha. and DR.beta. genes thus appear to be much less polymorphic than the previously described DQ.alpha. and DQ.beta. genes. Also, the observed linkage disequilibrium between DR genes was less pronounced than that between DQ genes, whereas the association between DR and DQ haloptypes was very strong. The family data available indicated strongly that the DQ.alpha., DQ.beta., DR.alpha. and DR.beta. genes are all closely linked.