Whole blood transcriptome analysis of feedlot cattle with and without bovine respiratory disease. Whole blood transcriptome analysis of feedlot cattle with and without bovine respiratory disease

In this study we aimed to identify differentially expressed (DE) genes involved in the host immune response to BRD using whole blood and RNA sequencing. Samples were collected from heifers (average arrival weight = 215.0 ± 5.3 kg) with (n = 25) and without (n = 18) BRD at a commercial feedlot in Western Canada. RNAseq analysis showed a distinct whole blood transcriptomic profile between BRD and non-BRD heifers. Further examination of the DE genes revealed that those involved in the host inflammatory response and infectious diseases pathways were enriched in BRD animals, while gene networks associated with metabolism and cell growth and maintenance were downregulated. Overall, the transcriptome profile derived from whole blood provided evidence that a distinct antimicrobial peptide driven host immune response was occurring in the animals with BRD. Overall design: 43 samples were collected from 25 cattle diagnosed with BRD and 18 pen matched controls at one time point.

本研究旨在利用全血样本与RNA测序（RNA sequencing）技术，筛选与宿主抗牛呼吸道疾病（Bovine Respiratory Disease, BRD）免疫反应相关的差异表达（differentially expressed, DE）基因。研究样本采集自加拿大西部某商业育肥场的青年母牛（初入栏平均体重为215.0±5.3 kg），其中确诊BRD的个体共25例（n=25），健康对照个体共18例（n=18）。RNA测序分析结果显示，感染BRD与健康青年母牛的全血转录组谱存在显著差异。对差异表达基因的进一步分析表明，BRD感染个体中富集了参与宿主炎症反应与传染病通路的基因，而与代谢、细胞生长及维持相关的基因网络则呈现下调趋势。综上，全血转录组谱分析结果证实，BRD感染个体体内存在以抗菌肽为核心驱动的特异性宿主免疫反应。实验整体设计：本研究在单个时间点采集了43份样本，其中25份来自确诊BRD的肉牛，18份为同栏匹配的健康对照样本。