Associations of the bovine major histocompatibility complex DRB3 (BoLA-DRB3) alleles with occurrence of disease and milk somatic cell score in Canadian dairy cattle

Abstract

Potential associations were investigated between bovine leucocyte antigen (BoLA) alleles and occurrence of disease. Cows (Holstein n = 835; Jersey n = 66) were examined for polymorphisms of the second exon of the BoLA-DRB3 gene, using the polymerase chain reaction (PCR), followed by digestion of the amplified fragments with three restriction endonucleases. Disease occurrences were recorded for each cow throughout one lactation. Milk somatic cell count data were retrieved through the Dairy Herd Improvement records and converted to somatic cell score (SCS). There were no effects of BoLA alleles on SCS in Jersey cows, but BoLA-DRB3.2*16 was significantly associated (P < or = 0.05) with lower SCS in Holsteins. Since the number of Jerseys was relatively small and prevalence of diseases in this population was low, health records of Jerseys were not analyzed further. BoLA associations with occurrence of disease in Holsteins were investigated using a log-linear model. There was a significant (P < or = 0.05) association between BoLA-DRB3.2*23 and occurrence of severe mastitis, from which coliforms were the most commonly isolated bacteria. The BoLA allele *3 was associated with a lower risk of retained placenta (P < or = 0.05) and alleles *16 (P < or = 0.05) and *22 (P < or = 0.05) with a lower risk of cystic ovarian disease. Although more studies are required to confirm the present findings, it can be concluded that BoLA alleles may have potential usefulness as genetic markers of higher or lower risk of disease occurrence in cows.

Breadth of the CD4+ T cell response to Anaplasma marginale VirB9-1, VirB9-2 and VirB10 and MHC class II DR and DQ restriction elements

“…We have identified highly antigenic CD4 + T-cell epitopes on T4SS proteins VirB9-1, VirB9-2, and VirB10 presented by BoLA class II DR and DQ molecules that are encoded by alleles prevalent among Holstein cattle worldwide. Similar frequencies of the MHC class II alleles studied here were found for Holstein cattle in Japan, where the combined frequencies were 81.2%, 86.9%, 90.3%, and 95.2% in four populations studied (Miyasaka et al, 2011; Takeshima et al, 2003), in Ontario, Canada, where the combined frequency was 89.5% (Sharif et al, 1998), in Iran, where the combined frequencies were 73.2%, 75.5%, 78.1%, and 80.2% in several studies (Nassiry et al, 2008; Pashimi et al, 2009), and in Europe, where the combined frequency was 89.5% (Nassiry et al, 2008). Inclusion of VirB9-1, VirB9-2, and VirB10 peptides linked together in a multiple-antigen and peptide-based vaccine will not only provide more than one immunogenic peptide, but will offer the opportunity for increased T-cell dependent IgG responses upon infection if B cell epitopes are also included (Morse et al, 2012).…”

GWA Analysis for Milk Production Traits in Dairy Sheep and Genetic Support for a QTN Influencing Milk Protein Percentage in the LALBA Gene

“…Notably, ovine QTL for FP [23] and for MY, FY, PY and FP [21] have been previously identified around the ovine MHC-II region in Spanish Churra sheep and a Sarda×Lacaune backcross population, respectively. Moreover, in the orthologous region of BTA23, QTLs influencing milk production traits have been described [41], with at least one gene located in the MHC-II region ( BoLA-DRB3 ) showing a reported association with milk dairy traits [42].…”

Breeding for resistance to mastitis in United Kingdom sheep, a review and economic appraisal

“…b o la-drb3.2*16 was significantly associated with lower scs (log transformed scc ) in Holsteins (P≤0·05), and there was a significant association between b o la-drb3.2*23 and the occurrence of severe mastitis (P≤0·05) (Sharif and others 1998). No corresponding studies in sheep have been reported.…”