[Analysis of DNA polymorphism of cluster genes in cattle: casein genes and major histocompatibility complex (MHC)...

The PCR-analysis method has been used to study polymorphism of casein genes (k- and b-caseins) and genes of class of basic histocompatibility complex (DRB and DQB BoLA) in some cattle breeds. Genotyping of k-casein locus has been carried out using analysis of protein polymorphism and DNA polymorphism. It is shown that both methods give identical results and can be used for this purpose, but the PCR-analysis method is more informative. A new allele of k-casein gene (k-Cn F) has been revealed and sequenced using the above method. While analyzing DNA-polymorphism of 5'-nontranslated region of b-casein gene two previously non-described polymorphic sites for restrictase Hinf I are found which occur only in animals of "zebu-like" breed. The high level of polymorphism of bl-domain of gene DRB is shown: polymorphism of bl-domain was revealed already at the level of electrophoretic analysis of PCR-amplification products. For 5'-nontranslated domain gene DQB the polymorphism level was much lower and manifested itself during restriction analysis of amplified fragments.