Single-cell transcriptomic analysis reveals the landscapes of key metabolic tissues in lactating dairy cows

The complicated biological process of how dairy cows convert indigestible nutrients for humans into nutritious milk is orchestrated by various tissues. Here, we deciphered the single-cell landscapes of 10 bovine tissue types covering 88,013 cells. We characterized the metabolic features of epithelial cell subtypes that exert unique functions to the tissues of residence. We also identified the cell subtypes that are essential for the transport of certain nutrients. Th17 cells were specifically enriched in the rumen, reticulum, and omasum tissues and predominantly interacted with the epithelial cell subtypes with high potential uptake capacities of short-chain fatty acids through IL-17 signaling. The comparison between IL17RAhighIL17RChigh cells and other cell types explained the important role of Th17 cells in regulating the epithelial cellular transcriptional response to nutrients transport in these three tissues. The findings enhance our understanding of ruminants biology and open new avenues for an improved animal production in dairy cows. Single-cell RNA sequencing for 88,013 cells from 9 tissues types of dairy cow.

奶牛将供人类食用的难消化营养物质转化为优质牛乳的复杂生物学过程，由多种组织协同调控。本研究解析了覆盖88013个细胞的10种牛组织单细胞转录组图谱，系统表征了驻留于各组织并发挥独特功能的上皮细胞亚型的代谢特征，同时鉴定出对特定营养物质转运至关重要的细胞亚型。辅助性T细胞17（Th17）特异性富集于瘤胃、网胃和瓣胃组织，并主要通过白细胞介素-17（IL-17）信号通路与具备高短链脂肪酸摄取潜能的上皮细胞亚型发生相互作用。对白细胞介素-17受体A（IL17RA）高表达、白细胞介素-17受体C（IL17RC）高表达细胞与其他细胞类型的比较分析，阐明了Th17细胞在调控这三种组织中上皮细胞针对营养物质转运的转录应答过程中所发挥的重要作用。本研究结果加深了我们对反刍动物生物学特性的理解，并为优化奶牛养殖生产提供了新的研究方向。本研究对来自9种奶牛组织的88013个细胞进行了单细胞RNA测序。