Submitted to: Plant and Animal Genome VX Conference Abstracts
Publication Type: Abstract only
Publication Acceptance Date: 11/22/2004
Publication Date: 1/14/2005
Citation: Burton, J.L., Madsen, S.A., Chang, L., Weber, P.S., Rosa, G.J., Matukumalli, L.K., Sonstegard, T.S. 2005. Expression profiles and snp analysis of genes that regulate neutrophil apoptosis, endothelial adhesion, and extracellular matrix remodeling at parturition in dairy cows. Plant and Animal Genome XIII,204, pp. 694. San Diego, CA [Abstract]. Interpretive Summary: THIS IS AN ABSTRACT. NO INTERPRETIVE SUMMARY REQUIRED.
Technical Abstract: Neutrophils are best known for their antibacterial activities (phagocytosis and killing). Previous studies documented that neutrophil bactericidal functions are depressed around parturition in dairy cows, possibly explaining the heightened susceptibility to mastitis and metritis at this time. We profiled gene expression changes in blood neutrophils of periparturient Holsteins to try and explain this phenomenon, and used BOTL cDNA microarrays (see http://www.nbfgc.msu.edu) and follow up quantitative real time RT-PCR to do so (see Madsen et al., 2004 Physiol. Genomics 16:212-221). Unexpectedly, we found that the predominant clusters of genes with changed expression at parturition were involved in neutrophil apoptosis (GR alpha, A1, Bak, Fas, FasL, TRAF-6, TANK, DAP5, BAFF, PSST), transendothelial migration (CD62L, CD18, IL-8, IL-8R beta), and extracellular matrix degradation (MMP-8, MMP-9, TIMP2, TIMP3, TGF-beta, and Granzyme B), but not phagocytosis or killing. Expression profiles of these genes correlated strongly with blood cortisol profiles, suggesting that this key steroid of parturition orchestrates important adaptive changes in blood neutrophils that result in decreased peripheral tissue trafficking, extended longevity, and enhanced tissue remodeling capacity (needed for cervical dilation and fetal membrane rupture). Our long-term goal is to identify molecular genetic markers of dairy cow health. Thus, genome sequence trace files encompassing the differentially expressed genes are being analyzed using SNP-PHAGE, a machine learning algorithm for SNP discovery. SNP validation and allele frequency estimation will be determined using a panel of bulls representing all major Holstein sires, and will focus on genes that reside near potential QTL for dairy production and health.