Examination of the pharyngeal tonsil transcriptome response to Bovine herpesvirus 1 (BoHV-1) infection in dairy calves

Bovine Herpesvirus 1 (BoHV1) is a leading cause of Bovine Respiratory Disease (BRD) in young calves, which is responsible for substantial morbidity and mortality. Therefore, the objective of the current study was to elucidate the mRNA transcriptomic response in pharyngeal tonsil tissue to an experimental challenge with BoHV1, in dairy calves. Holstein-Friesian calves were either challenged by intranasal atomisation with BoHV1 virus (6.3 x 10^7/mL x 1.35mL) (n=12) or mock challenged with sterile phosphate buffered saline (n=6). Clinical signs were scored daily until euthanasia at day 6 post-challenge. Total RNA was extracted and sequenced from pharyngeal tonsil (100 bp paired-end). Sequence reads were aligned to the ARS-UCD1.2 bovine reference genome and differential gene expression analysis was performed using EdgeR. Anlysis uncovered a total of 1833 differentially expressed genes (p < 0.05, FDR < 0.1, fold change > 2) between the BoHV-1 challenged and control calves. Overall design: Examination of a single tissue type (pharyngeal tonsil) in two different treatment groups, BoHV-1 challenged calves (n=12) and control calves (n=6)

牛疱疹病毒1型（Bovine Herpesvirus 1, BoHV1）是引发犊牛呼吸道疾病（Bovine Respiratory Disease, BRD）的主要病原，可造成严重的发病与死亡负担。本研究旨在阐明奶牛犊牛咽部扁桃体组织在经实验途径感染BoHV1后的mRNA转录组应答特征。实验将荷斯坦-弗里西犊牛分为两组：实验组采用鼻内雾化方式接种BoHV1病毒（浓度6.3×10^7/mL，接种体积1.35mL，样本量n=12）；对照组则以无菌磷酸盐缓冲盐水进行模拟接种（样本量n=6）。每日对犊牛的临床症状进行评分，直至感染后第6天实施安乐死。采集咽部扁桃体组织提取总RNA并开展100 bp双端测序。将测序读段比对至ARS-UCD1.2牛参考基因组，采用EdgeR软件进行差异基因表达分析。分析结果显示，BoHV1感染组与对照组犊牛间共鉴定出1833个差异表达基因（p < 0.05，错误发现率（False Discovery Rate, FDR）< 0.1，倍数变化>2）。本实验整体设计为：对两个处理组（BoHV1感染组n=12、对照组n=6）的单一组织类型（咽部扁桃体）开展转录组学分析。