Association analysis of bovine bactericidal/permeability-increasing protein gene polymorphisms with somatic cell score in Holstein cattle

Authors: Connor, Erin; MATUKUMALLI, LAKSHMI - GEORGE MASON UNIVERSITY; CHOCKALINGHAM, ANNA - PENN STATE UNIVERSITY; Bannerman, Douglas; Sonstegard, Tad; Thomas, Erika; Van Tassell, Curtis - Curt

Submitted to: Animal Genetics
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/11/2008
Publication Date: 4/16/2008
Citation: Connor, E.E., Matukumalli, L.K., Chockalingham, A., Bannerman, D.D., Sonstegard, T.S., Thomas, E.D., Van Tassell, C.P. 2008. Association analysis of bovine bactericidal/permeability-increasing protein gene polymorphisms with somatic cell score in Holstein cattle. Journal of Dairy Science. 39:456-457.

Interpretive Summary: Gram-negative bacterial infection is a principal cause of clinical mastitis in dairy cattle and the disease is one of the most costly to animal production agriculture. A naturally occurring protein called BPI functions in host defense against such bacterial infections. Therefore, BPI status of dairy cows may be related to their susceptibility to Gram-negative bacterial infections, including mastitis. The goals of the present study were to identify variation within the BPI gene of cattle and to determine whether there is an association between variation in this gene and mastitis susceptibility. Identification of such an association would benefit the dairy industry by providing valuable genetic markers for mastitis susceptibility. A genetic analysis of more than 2,100 contemporary Holstein sires indicated that variation in the bovine BPI gene is not associated with susceptibility to mastitis.

Technical Abstract: Bactericidal/permeability-increasing (BPI) protein is expressed primarily in bovine neutrophils and epithelial cells and functions as a binding protein of bacterial lipopolysaccharide produced by Gram-negative bacteria. The protein is important in host defense against bacterial infections and may play a role in mastitis. A QTL for somatic cell score in dairy cattle has been identified near the BPI locus. Therefore, the purpose of this study was to determine whether polymorphisms in the bovine BPI gene are associated with daughter yield deviation for somatic cell score in Holstein cattle. Thirteen SNP were identified in the bovine BPI gene from a panel of contemporary U.S. dairy sires, of which one (61G>A ) results in an amino acid (GlyàSer) substitution in the leader peptide of the protein, and another (126C>T) that results in a synonymous change near the donor splice junction of Exon I. It was determined from eight well-scored BPI SNP among 84 Holstein sires that four haplotypes represented approximately 98% frequency of the total haplotypes expressed in the population. However, there was no association between the eight haplotypes and daughter yield deviation for somatic cell score, an indicator of mastitis susceptibility. In addition, a linear model estimate of additive allelic differences derived from 2,132 Holstein bulls for the 61G>A and 126C>T polymorphisms indicated no effect of these mutations on daughter yield deviation for somatic cell score. Thus, our results indicate that variation in the BPI gene is not associated with mastitis susceptibility in Holstein cattle.