Characterization of bovine MHC class II DRB3 diversity in South American Holstein cattle populations

摘要: Holstein cattle dominate the global milk production industry because of their outstanding production, however, this breed is susceptible to tropical endemic pathogens and suffers from heat stress thus fewer populations are raised in areas. The bovine major histocompatibility complex (BoLA)-DRB3 class II gene used as a marker for disease immunological traits, its polymorphism has been studied extensively temperate cold regions. We genetic diversity BoLA-DRB3 South American determine whether have diverged those bred regions by selection and/or crossbreeding with local native breeds. specifically Exon 2 855 individuals polymerase chain reaction (PCR) sequence-based typing method. found high degree at allelic (Na > 20 He 0.87) molecular (π 0.080) levels, but low population structure (FST = 0.009215). A principal components analysis tree showed that Bolivian subtropical had largest divergence compared Holsteins or regions, was closely related Creole cattle. Our results suggest can be explained introgression germplasms. This first examination adapted environments, contributes an ongoing effort catalog MHC allele frequencies location.