Gene Expression Profiles Of Mastitis Artifitially Induced By Staphylococcus Aureus In Chinese Holstein

This experiment aimed to explore the gene expression changes and rules after dairy cattle were infected with staphylococcus aureus. Using gene expression profile chip to screen for differentially expressed genes and real-time Q-PCR technology to verify part of them, this study managed to find out the key candidate genes in the process of immune response against staphylococcus aureus type mastitis in dairy cattle.Three healthy Chinese holstein cows were selected as subjects, and administered with staphylococcus aureus into their mammary gland to induce the experimental mastitis. When mastitis was confirmed through observation of their body reaction24h after infection and by clinical diagnosis and SCC, the mammary gland tissue samples of tested cows were collected by surgical operation and assayed differentially expressed genes using Agilent cow genome expression profile chips. Those differentially expressed genes were then analyzed by GO and Pathway analysis for functional notation and biological significance. Part of these genes associated with immunity were verified by Q-PCR. The main results are as follows:1. Microarray analysis screened out297significantly differentially expressed genes, of which188genes were upregulated and109downregulated (FC>2, P<0.05).2. These significantly differentially expressed genes were analyzed by GO analysis, indicating that these genes were involved with151GO Terms (P<0.05).3. Pathway analysis of these differentially expressed genes screened out a total of15significant Pathway:Hematopoietic cell lineage, Cytokine-cytokine receptor interaction, Chemokine signaling pathway, Natural killer cell mediated cytotoxicity, Primary immunodeficiency, MAPK signaling pathway, T cell receptor signaling pathway, Antigen processing and presentation, B cell receptor signaling pathway, Intestinal immune network for IgA production, Wnt signaling pathway, PPAR signaling pathway, Toll-like receptor signaling pathway, Jak-STAT signaling pathway, and VEGF signaling pathway.4. Network planning analysis of these pathways screened out a total of32hub genes: BoLA-DRB3, BoLA-DRA, BLA-DQB, CSF3, CTLA-4, PIK3R3, TGFB, FASLG, LSC126945, MAP2K1, MAP2K3, EPAS1, GNA12, PRKACB, TCF7, GNB, TWIST2, IL17A, IL4R, IL1R2, NOS2, SELE, ZAP70, JAM3, CD80, CD3D, TLR8, NCF1, LOC509513, MMP2, FCGR1A, and WNT2. those hub genes were important and could be used as candidate genes to control staphylococcus aureus mastitis in dairy cattle.5. Part of significantly differentially expressed genes, e.g. C3, TLR8, BoLA-DRB3, PTX3, CSF3, SLC11A1, CD80, and IL17A, were verified using Q-PCR method. The results exposed the consistency between Q-PCR analysis and statistical analysis of microarray data of differentially expressed genes.