Major Histocompatibility Complex Class II (DRB3) Genetic Diversity in Spanish Morucha and Colombian Normande Cattle Compared to Taurine and Zebu Populations
Fecha de publicación: 10/01/2020

Bovine leukocyte antigens (BoLA) have been used as disease markers and immunological
traits in cattle due to their primary role in pathogen recognition by the immune system. A
higher MHC allele diversity in a population will allow presenting a broader peptide repertoire.
However, loss of overall diversity due to domestication process can decrease a
population’s peptide repertoire. Within the context of zebu and taurine cattle populations,
BoLA-DRB3 genetic diversity in Spanish Morucha and Colombian Normande cattle was
analyzed and an approach to estimate functional diversity was performed. Sequencebased
typing was used for identifying 29, 23, 27, and 28 alleles in Spanish Morucha,
Nariño-, Boyacá-, and Cundinamarca-Normande cattle, respectively. These breeds had
remarkably low heterozygosity levels and the Hardy-Weinberg principle revealed significant
heterozygote deficiency. FST and DA genetic distance showed that Colombian Normande
populations had greater variability than other phenotypically homogeneous breeds, such as
Holstein. It was also found that Spanish Morucha cattle were strongly differentiated from
other cattle breeds. Spanish Morucha had greater divergence in the peptide-binding region
regarding other cattle breeds. However, peptide-binding region covariation indicated that
the potential peptide repertoire seemed equivalent among cattle breeds. Despite the
genetic divergence observed, the extent of the potential peptide repertoire in the cattle
populations studied appears to be similar and thus their pathogen recognition potential
should be equivalent, suggesting that functional diversity might persist in the face of
bottlenecks imposed by domestication and breeding.