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To enhance the healthful characteristics of milk fat through increases in conjugated linoleic acid (CLA), oleic acid and the omega-3 fatty acids. To understand the regulation of stearoyl-CoA desaturase (SCD) using stably labeled fatty acid substrates in order to maximize the content of healthy fatty acids in milk. To characterize the ruminant: Escherichia coli O157:H7 interactions in order to improve the safety of beef. To prevent and control mastitis through an understanding of the host's response to Staphylococcus aureus and its endotoxins.
Changes in gene expression of cattle can be evaluated a number of ways. A relatively new technique is the assessment of gene expression through microarray analysis. This approach allows for simultaneous evaluation of thousands of genes. A scanner is necessary to obtain the data from the microarray. The microarray scanner will allow evaluation of the gene expression in cattle to improve milk quality, improve food safety and to enhance animal health. The scanner will be used in experiments that alter the fatty acid profile of milk, examine the factors by which Escherichia coli O157:H7 resides in cattle and understand how the cow responds to Staphylococcus aureus in mastitis.
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Changes in gene expression in bovine tissues will be evaluated using bovine-specific microarrays. Biopsies of mammary, adipose and liver tissue will be obtained during treatments that alter milk composition. Bovine tissues will also be examined before, during and after the presence of Escherichia coli O157:H7 to evaluate if specific genes are important in the host response. Further, gene expression in mammary tissue in the whole animal and in vitro cell cultures exposed to Staphylococcus aureus will be studied. In all studies, RNA will be extracted from bovine tissues and utilized in microarray analysis.