Expression data from mouse model of Ecoli mastitis

We performed a genome-wide transcriptional analysis in the mammary gland in a mouse model of E. coli mastitis using high-density mouse oligonucleotide microarrays. This global transcription analysis revealed that about 7% of tested genes are mobilized in the mouse mammary gland to E. coli endotoxin. We identified 1402 differentially expressed genes that were associated with physiological system development/function and molecular/cellular functions and metabolic/signalling pathways that are highly relevant to host immune-inflammatory defense response against E. coli infection. The mouse differentially expressed genes through the use of comparative mapping/genomics and positional information on reported QTL for bovine mastitis allowed identifying 293 potential candidate genes for bovine mastitis. This study will enable other researchers to combine our mRNA expression data with genetic association studies to discover genomic variation underlying variation of susceptibility to mastitis in dairy cows. Keywords: time course, disease state analysis Overall design: This study was conducted using a split-plot design. We measured levels of gene expression in healthy (saline injected) and diseased (E. coli injected) mammary gland tissue (treatment = 2, in sub-plots). The mammary tissue samples were collected at two-time points: 24 hr and 48 hr post-injection (time = 2, in main-plots). Each inbred mouse was injected with both treatments: the 4th left mammary gland was injected with saline solution and the 4th right mammary gland was injected with E. coli solution (mice = 4). The expression profiling was carried out using two biological replications (replication = 2) at each time point.

本研究采用高密度小鼠寡核苷酸微阵列，对大肠杆菌乳腺炎小鼠模型中的乳腺进行了全基因组转录组学分析。这一全局转录分析揭示了约7%的测试基因在乳腺中响应大肠杆菌内毒素而被激活。我们鉴定出1402个差异表达基因，这些基因与生理系统发育/功能、分子/细胞功能以及与宿主对大肠杆菌感染免疫炎症防御反应高度相关的代谢/信号通路相关。通过比较基因组学/基因定位与已报道的奶牛乳腺QTL的位置信息，我们识别出293个潜在的奶牛乳腺候选基因。本研究将使其他研究人员能够将我们的mRNA表达数据与遗传关联研究相结合，以发现奶牛乳腺炎易感性的基因组变异。关键词：时间进程，疾病状态分析。总体设计：本研究采用裂区设计进行。我们测量了健康（盐水注射）和疾病（大肠杆菌注射）乳腺组织中的基因表达水平（处理因素=2，在副区）。乳腺组织样本在两个时间点收集：注射后24小时和48小时（时间因素=2，在主区）。每只纯合小鼠均接受两种处理：左侧第4个乳腺注射盐水溶液，右侧第4个乳腺注射大肠杆菌溶液（小鼠因素=4）。在每个时间点，采用两次生物重复（重复因素=2）进行表达谱分析。