Project description:In a time course study, we characterized global gene expression profile of B. abortus-infected macrophages from cattle naturally resistant (R) and susceptible (S) to brucellosis. B. abortus infection causes early down-regulation of transcript levels in Mø from R cattle at 4 h p.i. (22 up- and 126 down-regulated genes) which is reversed by 12 h post-infection (31 up- and 25 down-regulated genes), compared to uninfected control. On the other hand, B. abortus-infected S bovine macrophages exhibited a down-regulated expression profile at 4 (45 up- and 65 down-regulated genes) and 12 h p.i. (47 up- and 193 down-regulated genes). The analysis of the results indicates that B. abortus – infected Mø from cattle naturally R and S to brucellosis display different transcriptional profiles. Specific genes and biological processes identified in this study will further help elucidate how different macrophages from resistant and susceptible animals interact with Brucella during the early infectious process. Keywords: Expression profiling by microarray